[Latex] Match sizes using dots as optional argument to newline command (

sublimehq#1761)

Previously, commands like `\\[1.5ex]` that use a dot in the size were not matched correctly (while `\\[1ex]̀  was recognized). This is fixed.

LaTeX/LaTeX.sublime-syntax

@@ -165,7 +165,7 @@ contexts:
         - include: macro-braces
 
   general-constants:
-    - match: '(\\\\)(?:(\[)\s*-?([[:digit:]]*)\s*(\w*)\s*(\]))?'
+    - match: '(\\\\)(?:(\[)\s*-?((?:[[:digit:]]|\.)*)\s*(\w*)\s*(\]))?'
       captures:
         1: constant.character.newline.latex
         2: punctuation.definition.group.bracket.begin.newline.latex

LaTeX/syntax_test_latex.tex

@@ -55,6 +55,19 @@
 % ^ support.function.begin.latex keyword.control.flow.begin.latex
 %        ^ variable.parameter.function.latex
 
+
+% TEX INTERNAL COMMANDS
+\\
+% <- constant.character.newline.latex
+
+\\[1.5ex]
+% <- constant.character.newline.latex
+% ^ punctuation.definition.group.bracket.begin.newline.latex
+%  ^^^ constant.numeric.newline.latex
+%     ^^ keyword.other.newline.latex
+%       ^ punctuation.definition.group.bracket.begin.newline.latex
+
+
 % SECTION COMMANDS
 
 \part{name}