gcc: cleanup of code
gcc: add support for multilib
Merge branch 'develop' into gcc

* develop:
  fix typo
  don't hardcode default values for extra options
  refactor to make all extra_options return a list of tuples rather than a dict, conform the framework v1.x API
  enhance unit tests to verify type of return value of extra_options() static method
  refactor extra_options in existing easyblocks
  fix unit tests after changes in framework
  fix unit tests after changes in framework
  fix defining tmp_logdir config setting
  imkl: small remark in sanity check
  imkl: updated sanity check
  imkl: make version check more correct
  Reworked after remarks
  imkl: some cleanup and added some libs to the sanity check
  imkl: install everything with version 11.1.1
  IntelBase: allow to add lines to silent.cfg
  fix ordering in import line
  fix typo
  fix readline module specs in Modules/Setup.dist
  add sanity check for readline

Conflicts:
	easybuild/easyblocks/g/gcc.py
gcc: multilib remark correction
gcc: fix indenting
gcc: update glibc 32 bit names
Merge pull request #379 from wpoely86/gcc

GCC multilib support