Fix the tm_scope for Less

The source.css.less grammar actually understands Less syntax.
Merge pull request #1703 from github/less-tmscope

Fix the tm_scope for Less
Add a tm_scope for GAS

The source.asm.x86 grammar does a decent job of parsing this.
Merge pull request #1704 from github/gas-tmscope

Add a tm_scope for GAS
Update the TM scope for the Zephir language
Bump to version v3.5.2
Merge pull request #1705 from github/cut-release-v3.5.2

Bump to version v3.5.2
Add FORTRAN samples.
Add Forth extensions .f and .for; add heuristics for Forth and FORTRAN.