Add ErlangCheck check:
    - beam-compiled-without-debug_info to test that beam properly compiled
    - beam-was-not-recompiled to test that beam recompiled at rpmbuild
Rename CheckErlang.py -> ErlangCheck.py
Use RPM macros %_builddir instead of config variable.
Rename CheckErlang test to ErlangCheck
Add DummyErlangCheck for cases, when pybeam is not loaded.