#494 pic14 port tests

[daniel kucharski]

Hello,
I have found a way to improve pic14\pic14e regression tests.

1. replace -O2 with -O0. enabling optimization stop tests from proper messages to gpism
2. add linker scripts for 16f877 and p16f1788 tests micros
3. suit Makefile to run with linker scripts
4. small change in src/pic14/glue.c - remove absolute address for STARTUP and c_interrupt

regression tests pass - run with
make test-pic14
make test-pic14e

Regards,
Daniel Kucharski