honour --cython-only option in compiled unit tests and pyregr tests
simplify evaluation of --cython-only option in test runner
remove Py2.3 work-around
remove duplicated code
support Ellipsis as compile time constant
fix constant folding for repeated negation
minor code cleanup
add constant folding tests for bool values
delete unused LongNode class
fix expression node finding for bool and character values in constant folding
fold sliced literal sequences (e.g. from DEFs) into constants
add constant folding test for sliced unicode and bytes literals
refactor constant string slicing and guard it against platform specific unicode string length
only include CythonFunction utility code if it's really used, might be unused if .pxd overrides all def functions to cdef
move string related utility functions from Optimize.c and Optimize.py to StringTools.c
move tp_new() utility code into ObjectHandling.c
make call signature of method dispatch usable for both simple and general call nodes
implement tp_new() optimisation with args/kwargs
optimise tp_new() for module-internally defined types by calling the tp_new slot function directly