gcc-c-api: add is_unsigned attribute to gcc_integer_type
gcc-c-api: autogenerated all of the various casting functions
autogenerate the various PyGccTree_as_ casting functions
add "location" attribute to 7 tree types
gcc-c-api: add "operand" attribute to gcc_unary
fix crash due to misssing type-checking of 2nd argument of PyGccLocation_richcompare
gcc-c-api: add "is_loop_exit" and "can_fallthru" flags to gcc_edge
fix dot generation for CFGs to reflect the edge changes made in 0519ff959476d77c1f650914e19d2b7aace37dcf
bulletproof dot generation against stmt.loc == None
add an optional "name" argument to invoke_dot
whitespace fixes
fixes to dynamic linking

Previously python.so was dynamically linked against "gcc-c-api/gcc-c-api.so", leaving a:
   NEEDED            Shared library: [gcc-c-api/gcc-c-api.so]
within its ELF metadata, which can only be resolved from a working copy.

Rename the library to libgcccapi.so, and fix things so that we link the
plugin against -lgcccapi, passing in -L so that it can find it when
python.so is linked.

This requires us to pass in LD_LIBRARY_PATH when invoking the plugin from
a working copy (or from elsewhere in the filesystem), but does allow the
plugin to be invoked from an arbitary location in the filesystem
(we may need to add an RPATH to python.so for installation).
gcc-c-api: ensure that the generated casts don't get name-mangled
gcc-c-api: add "initial" and "is_static" attributes to var_decl
gcc-c-api: add "operand" attribute to gcc_addr_expr
gcc-c-api: add "char_ptr" attribute to gcc_string_constant
add "array" and "index" attributes to gcc_array_ref
gcc-c-api: add "target" and "field" attributes to gcc_component_ref
gcc-c-api: introduce gcc_option
fix stray character