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
Use source.fortran.modern TM scope for FORTRAN

This is technically only for FORTRAN 90 and newer, but seems to do just fine with older variants.
Merge pull request #1708 from github/fortran-modern

Use source.fortran.modern TM scope for FORTRAN
Add assert for Emacs lisp

/cc https://github.com/github/linguist/pull/1499
Merge pull request #1709 from github/emacs-lisp-assertion

Add assertion for Emacs Lisp