Impl. extensions, fixes, optimizations, improve docs and readability, etc.

- Fix: missing first line of each type definition ("class Type {") when namespace is not specified.
- Fix: removed PHP code closing to avoid "Headers already sent" or similars, in both wsdl2php and generated code.
- Fixed lots of warnings, notices, deprecations, etc.
- PHPDoc: "ArrayOfType" should become "Type[]" and not "array Type".
- Performance: use strpos() instead of strstr() to check substring presence.
- Readability: fixed indentation using tabs in generated code.
- Readability: write variable documentation and definition on the same line in generated code.
- Generated code is almost halved in size.