Squashed 'syntax/' changes from 0247f03..06d01ef

06d01ef remove haxeErrorCharacter from regex segments
6ce99e7 minor fix for hxml syntax styling
f0d45cf add hxml syntax for Haxe3's new compile option
13dcfa1 updated syntax with lucas changes
1dac759 move readme to the right file format
a24e7b8 Merge commit '7a747363e3ee6e61f9f3c01ba44f5fc86522b839'
0327dc4 updated haxe syntax with Lucas work, split of extra syntax specs to a haxe_extended syntax
6b1aa40 add #elseif conditionals to syntax

git-subtree-dir: syntax
git-subtree-split: 06d01ef379a1fa0f32ccbee220690f920b2a41e4
fix syntax conflict