Scatter shot

this started as a few harmless low level parser fixes, but became a full blown crusade to replace all exceptions which are thrown due to parse errors by log messages. (After this, we are wading in a sea of log messages stemming from heretic exceptions. ;) This means that exceptions seeping out of by the EclipseState or Opm::Parser classes due to any invalid input deck should be considered to be bugs in either the calling code or in opm-parser itself after this PR has been fully merged

this series is quite long, but it has been verified to be fully bisectable using GCC 4.4 and Clang 3.5 and also that sim_fibo_ad still works for SPE-1, SPE-9 and Norne. If you don't want to review and merge it in one go because of its longness, I propose that you review a few patches at a time and I'll open a new PR for these once you indicate that you'd like to stop there. (make sure to review them in "git order" as github screws up on the ordering of rebased patches.)