PHP generated code match PSR-2

When use thrift compiler to generate PHP code, there are many issues doesn't match PSR-2

• indent by 2 spaces, PSR-2 require 4 spaces.
• Opening brace should be on a new line (for function)
• The static declaration must come after the visibility declaration
• etc.

So, we can make generated code more readable, match PSR-2(almost).