Initial draft of expander mechanism with StartsWith expander example

Replaced [] with array() in AST\Expander class for php 5.3 support

Refactoring

Added Boolean and Null argument types support

Added negative numbers support

Added  argument to StartsWith expander

Set Lexer as a dependency of Parser and Parser as a dependency of StringMatcher

Added possibility to add new expander definitions

Added notBlank expander

Changed expanderName definition

Added lowerThan expander

Implement expanders in IntegerMatcher

Added expanders to DoubleMatcher

Added GreaterThan expander

Added EndsWith expander

Renamed NotBlank into NotEmpty

Added array argument type support

Added InArray expander

Added Contains expander