Mongoose 6.8

PUBLISHED_FROM=082d0bf5e9b06b850382ce502c7f5b4d68a6a328

Which is a slightly modified version from
https://stackoverflow.com/questions/283166/easy-way-to-convert-a-struct-tm-expressed-in-utc-to-time-t-type

PUBLISHED_FROM=b73f920ca42c45473c23337782e815306bdf69f1

PUBLISHED_FROM=4ddfc25af77247fac7e7d04cc0e56d6f3800f87b

PUBLISHED_FROM=7bbe7dd20dca8435c786dca30200a4973ae0827d

PUBLISHED_FROM=07e820f539fa5feca2ad1cf81faca8404b773a65

PUBLISHED_FROM=b7325b38e881455df703b0b628c41931565ccb33

PUBLISHED_FROM=6f2d9849d75ca1ec2b6dade11ccad8d0c5d4b3bd

Add checks on the number of subscribe requests per packet and overall per-session subscription limit.

PUBLISHED_FROM=faaf5c50af31a0694c9308a664f2e418dbb0eb18

PUBLISHED_FROM=e16ee57bc30277e5b5684e53da78e69baaf9f779

PUBLISHED_FROM=263553121b992ec0f66b0275b4e10f4176281812

PUBLISHED_FROM=5831462c5be0b79afff32130a1f45784f32bc524

PUBLISHED_FROM=db89a45a536f0234d6d5cf740354c0dbeeff1f26

```
Using port /dev/ttyACM0
[Aug 30 19:33:02.105]
[Aug 30 19:33:02.114] cc32xx_init          c_no_libs 1.0 (20170830-163205/mos8@6587ffd6+)
[Aug 30 19:33:02.123] cc32xx_init          Mongoose OS 2017083016 (20170830-163205/mos8@6587ffd6+)
[Aug 30 19:33:02.130] cc32xx_init          RAM: 253588 total, 240044 free
[Aug 30 19:33:04.430] cc32xx_start_nwp     NWP v3.4.0.0 started, host driver v2.0.1.19
[Aug 30 19:33:04.437] mgos_vfs_dev_open    slfs_container ({"prefix": "spiffs.img.0"}) -> 20005a64
[Aug 30 19:33:04.450] cc32xx_vfs_dev_slfs_ 20005a64 spiffs.img.0.0 262144 0xfffffffffffffffe
[Aug 30 19:33:04.457] mgos_vfs_mount       Mount SPIFFS @ / (dev 20005a64, opts ) -> 20005a74
[Aug 30 19:33:06.102] mgos_vfs_mount       /: size 233681, used: 4016, free: 229665
[Aug 30 19:33:06.108] mgos_vfs_mount       Mount SLFS @ /slfs (dev 0, opts ) -> 20005ed4
[Aug 30 19:33:06.114] mgos_vfs_mount       /slfs: size 0, used: 0, free: 0
[Aug 30 19:33:06.718] mgos_sys_config_init MAC: 04A316459442
[Aug 30 19:33:06.720] mgos_sys_config_init WDT: 30 seconds
[Aug 30 19:33:06.724] Hello, world!
[Aug 30 19:33:06.728] mgos_init            Init done, RAM: 253588 total, 236544 free, 235864 min free
```

PUBLISHED_FROM=7e83c9ddcc642bd324a40e125d6636ece824fb18

For now, we only support SPIFFS-in-a-box, same as CC3200.
On CC3200SF it should be possible to have SPIFFS on built-in flash, but that is left for later.

PUBLISHED_FROM=dee337c8cd8ed288c22abe9960eef81e6e90cc4a

PUBLISHED_FROM=5e7fcc7bf145aa8e1045e8d627b1c0731bb4341b

Also, do not accept PUBLISH and SUBSCRIBE before a sucessful CONNECT.

PUBLISHED_FROM=b5096cdc2ec5da1358244c428efbbb2e20be1a05

Also make CC3200 use newer ARM compiler, generates slightly smaller code.

PUBLISHED_FROM=a0be49d7ea864a95886f7110887a59f6f11802d7

And mgos_conf_check_access_n()

PUBLISHED_FROM=c7de937b4f5463ca463d604183a4ee831617bd6d

Achievement unlocked: CC3220 port prints a boot banner.
Then locks up.

Included in this PR is refactoring to pull out common parts to be shared with CC3200.

PUBLISHED_FROM=5fb9d9a00bb9ce7f63dde20bc1876076b76d5257

Fixed bug in websocket handshake:
now adding Sec-WebSocket-Protocol header in handshake response.

PUBLISHED_FROM=e4a71ff9dc4aeec63db40cb7f356dc5b25c1215a

PUBLISHED_FROM=f97569ae2f31ab94ce4875eae4d0a198f719c388

https://forum.mongoose-os.com/discussion/comment/4620/#Comment_4620

PUBLISHED_FROM=679dd48e078615ef4f57d1879957b734f549ef2e

Ignore all the mess, this is just the beginning...

PUBLISHED_FROM=41ab3c5af0b1d07204619dd4d8dc2e84b6a54f32

PUBLISHED_FROM=73d6767e4aaa7249eeb5d76f9e7160be041292ca

PUBLISHED_FROM=62c73e5fb4f70e2b5b8824ce092012508640b173

PUBLISHED_FROM=7b9c85e7708721f2c6d0e2fc8ad5c32c61b48854

Fix headers that didn't have it

PUBLISHED_FROM=ce8140783d4b661f16278a4a5adc957b21965473

PUBLISHED_FROM=33957356e1510b73b37768496c74a6bf12630215

Change the API to heap-allocate the string and get rid of a bunch of fat stack buffers.

PUBLISHED_FROM=c793dc64a9a044a9769d92ea16859f5d704a2181

PUBLISHED_FROM=2fc7b59b2edd0f473acd22067439471778acef8e

PUBLISHED_FROM=ed2c39b9e00a7374af7fed5af0c9acd6c330334a

PUBLISHED_FROM=6e56c250fe62010e25b6ed489c0d608163ba629c

PUBLISHED_FROM=c6c31d47eedcfe09b675e3f56d967da5b22809f6

PUBLISHED_FROM=a0dd26c00b41363f1cc58c28f530fbdf272ed146

Also allow disabling conmpression and forcing server cipher list.

PUBLISHED_FROM=5539deec9c2382ba34597872dd7f3a5abc0cc311

PUBLISHED_FROM=4306e870e2cab854febb6becc198ca2247e2e002

PUBLISHED_FROM=4d4d49136e13ba8035d452a4f64fcaf48f15bdb3

PUBLISHED_FROM=f2821b104f8f2fc196ce4064b7c9f35ea152368d

Write unit tests for some mg_str functions.

PUBLISHED_FROM=1fc7e1d5d5ef259d4023f295aec8651caa3e7e86