[ops2c]: remove extraneous parentheses

no need for -Wno-parentheses-equality anymore.
Closes #1008
[cage] remove -Wno-parentheses-equality, SUFFIX OVERRIDE

Remove unneeded SUFFIX OVERRIDE for dynoplibs
cc_shared is not part of CFLAGS, so remove those special cases also
add -Wno-switch-default to generated compilers/imcc/imcparser.c

Tested with gcc49, clang3.5 and clang3.5++
[cage] adjust all warnings and overrides

no wrong warnings in parrot core anymore
tested: gcc4.4, gcc4.5, gcc4.6, gcc4.8, gcc4.9,
        clang3.5, clang3.5++, apple cc

remaining todo:
* --optimize -Wunused-parameter: interp used with ifndef NDEBUG
* -Wcast-qual with gcc, but these warnings are legit.
* stack usage: legit
[cage] spf_render.c UINTVAL_FMT: no %d format for UINTVAL
[cage] fix warn_unused_result with Parrot_set_new_context
[cage] panic if set_new_context fails
[cage] silence --optimize -Wunused-parameter warnings also