Fix infinite loop when triggered on first column on the line
Fix built-in classname and interface methods loading

Makes the built-in class names indexed with lowercase names
Makes the methods from interfaces saved with the actual interfacename
instead of a copy-paste induced last classname
Make callchains with static call in front resolved faster
Implement a smarter <C-]>

The plugin will try to guess the expression's class under cursor and jump
to the correct one instead of just matching the tagnames. Falls back to
the built-in method on failure.
The enhancement can be disabled with the new
g:phpcomplete_enhance_jump_to_definition option

This feature was first mentioned in #31.