Fix parsing token components with parenthesis without spaces (#254)

* fix parsing token components with brackets without spaces

* handle more edge cases

* do not use force unwrap

* use first/last instead of hasPrefix/hasSuffix

* update CHANGELOG

CHANGELOG.md

@@ -16,7 +16,9 @@ _None_
 
 ### Bug Fixes
 
-_None_
+- Fixed using parenthesis in boolean expressions, they now can be used without spaces around them.  
+  [Ilya Puchka](https://github.com/ilyapuchka)
+  [#254](https://github.com/stencilproject/Stencil/pull/254)
 
 ### Internal Changes