String and command improvements

Changelist:

• Fixed a bug where a command with an '=' character would be colored as an indented variable affectation
• Improved string coloration in variable affectation

Variable call in variable declaration

1.0.4

Fix variable usage in variable declaration + factorize redundant rule…

Multiline comments / Improved rule coloring

1.0.3

Merge branch 'master' of github.com:Altomare/sublime-makefile-plus

Improved multiline variables

Fix bug where variable definitions on multiple lines would be considered as multiple variable definitions.

Ex:
CPPFLAGS := -DLOG=1
-D_POSIX_C_SOURCE=1

Fix substitutions

Just a basic substitution fix

Initial release

Initial release for Package Control usage.