PHPCoverage Code

- [Bug: 30] Added T_INTERFACE to the list of tokens to be considered non-executable.

- [Bug: 21] Fixed so that try, switch keywords are non-executable.
- Applied patch for const keyword from Joerg. (http://developer.spikesource.com/forums/viewtopic.php?t=540)
- [Bug: 22] If there are no exeutable statements in a file, coverage is 100%

- Protecting lines with php close tags as strings.

- Added initial version of PHPCoverage from trunk