Swift 2 changes

closes #279

Fix C lexer w.r.t function declarations

For #277

These tokens were missing the specific regex match arguments, causing
duplicated output.

This fixes #277.

Fixing prolog lexer issue on camelCase atoms

Although camelCase atoms - as well as functor's and predicate's names -
are sometimes considered a bad practice, they are actually valid.

Before this commit, a camelCaseAtom would be highlighted as **camel**CaseAtom.
Now, it is properly highlighted as **camelCaseAtom**

Support drupal filename extensions in the php lexer

Disable not existing rules in C# lexer

see also: https://github.com/gitlabhq/gitlabhq/issues/8900

This patch disables some rules in the c# lexer which does not exist.

Reported by Douwe Maan: https://github.com/rumpelsepp/rugments/issues/12

Pass lexer options to enumeration to support continue use case

powershell syntax demo

Style changes requested by Jneen, Fixes for Attributes highlighting.

spacing issues

refactoring

Fix syntax in README's code example

Add comment and ellipsis support to json lexer.

Register JSON API mimetype for JSON lexer

Document the --formatter option

Fix bugs in liquid lexer (closes #237)