Flatten nested STMT_LISTs

Some nodes like ECHO always get wrapped in STMT_LIST, resulting in
some weird syntax trees.

Use AST_VAR node for static var + catch var

For version 20. Previously this was a simple string with the
variable name.

Fix child names for virtual nodes

Use version 30 for named children

Merge branch 'master' into stringChildren

Conflicts:
tests/binary_ops.phpt

Add CLASS_ANONYMOUS flag

Pointed out by @tpunt

Move AST_AND, AST_OR to AST_BINARY_OP as well

Use v20 instead, add to flag list

Added tests

Convert unary ops to flags of ZEND_AST_UNARY_OP

Use string child names for non-list nodes

Implementation needs some polishing.

Use X macro for global strings

I plan on adding more of these, so drop all the repetition.

Also add AST_STR() macro to abstract the naming convention.

Use BINARY_ flags for ASSIGN_OP as well

Makes it easier to work with if both use the same flags

Use AST_BINARY_OP instead of AST_GREATER(_EQUAL)

Version 20

Add $version parameter

Switch to zpp_throw

Zpp failures now result in a TypeError. All failure conditions
should be throwing now.

Added flag constants for AST_INCLUDE_OR_EVAL

The flags' integral values match the values defined in
Zend/zend_compile.h

Actually add the test...

Only use 3 children for AST_CLASS

Also add a test for class AST.

Use explicit int-to-string conversion

Add constants for POW, ASSING_POW, SPACESHIP

Update flags for group use declarations

Now the type may also be on GROUP_USE and USE_ELEM

Determine flag name when dumping

I don't know by heart which flag 67108864 is...

Test get_kind_name()

Also switch it to throw LogicException.

Improve AST_CLOSURE_VAR implementation

* Simplify code by combining nearly completely duplicate function
* Add AST_CLOSURE_VAR to generate_ast_data.php
* Add test
* Adjust README