Import: Add apex code hightlight suport

[pyrmont]

Import the "Add apex code hightlight suport jneen#1103" PR.

[pyrmont]

The filename spec is failing because both Tex and Apex can use the .cls file extension. I'm not sure what the best solution to this problem is.

[pyrmont]

Possibly relevant.

[pyrmont]

The solution is:

1. You need to specify a self.detect? method inside /lib/rouge/lexers/apex.rb file. This method will return true if the string being guessed matches a regex pattern that is unique to Apex class files. You can see an example of the kind of method in the TeX lexer.

2. In your spec, you need to pass an additional source: argument at this line that is a piece of text from the start of an Apex .cls file. You can see an example of what this looks like in the Prolog spec.

3. You need to edit the TeX spec to include a similar line here that passes a string that will be recognised by its self.detect? method. I'm not super familiar with TeX but it looks like the string '\ProcessOptions\relax' should work.

[pyrmont]

I was incorrect about points 1 and 3 in the earlier message. The correct place to put the disambiguation code is in lib/rouge/guessers/disambiguation.rb. The self.detect? method serves a different purpose.