add ubuntu specific note

git-svn-id: https://pycam.svn.sourceforge.net/svnroot/pycam/trunk@70 bbaffbd6-741e-11dd-a85d-61de82d9cad9

INSTALL.TXT

@@ -57,3 +57,11 @@ I unpacked the tcl and tk sources next to the Togl sources in my home directory,
         make 
 	make install
 
+
+For ubuntu:
+    (assuming you have tcl8.4, if not, replace 8.4 by 8.5 below)
+
+    install the packages "tcl8.4dev" and "tk8.4dev"
+    ./configure --with-tcl=/usr/share/tcltk/tcl8.4/ --with-tk=/usr/share/tcltk/tk8.4/ --enable-threads
+    make
+    sudo make install