Update chpl --version to use git sha1 and branch, instead of svn revision.

This updates BUILD_VERSION to store a string of the form "<branch>@<sha1>"
representing the branch and commit checked out in the workspace. That string is
the fourth part of the version number, when it is available.

This commit does not change behavior of when BUILD_VERSION is generated.
Remove FIXME from updateBuildVersion.
Wrapping up triage for the week

Here are the additional changes for REGRESSIONS that I didn't note
earlier in the week (Greg, I'll walk you through the important points
on email):

regress :(
----------
- new verification/valgrind failures due to one of noakes' cleanup passes and a bad
  interaction with dead code elimination (he's on it)
- cray-prgenv-cray now...
  - fails C I/O tests
  - fails the filerator tests for portability reasons like most of the
    other whitebox configs
  - fails due to the empty struct in 794131 (lydia has since fixed)
- whitebox testing
  - has some lingering "empty directory" failures due to git conversion due to
    being a half week behind (should be fixed on next run)
- cygwin testing (full suite) now...
  - gets strict overflow warnings like darwin and whitebox gcc testing due to new gcc
  - gets aggressive-loop-optimization warnings like "
  - gets a number of I/O-related failures (Michael has been notified)
  - sees chpldoc failures due to sorting ordering (as far as I can tell)
  - generates a strange failure mode for static_dynamic (didn't look into it)
  - gets RLIMIT_NPROC undefined problems on TooManyThreads
  - gets CHPL_RT_CALL_STACK_SIZE too big warnings for a half-dozen tests
  - doesn't get the "query memory/problem size" testing correct

progress!
---------
+ removed qthreads threadring timeout
+ regexdna no longer valgrind failing thanks to Tim + Ben
+ cray-prgenv-cray no longer...
  + has missing string arguments in two tests' writelns
  + suffers from the CCE IPA bug
  + gets a signal 11 for distributions/robust tests
  + gets as many compilation timeouts as it used to (though several remain)
+ asserteof no longer seems to fail for intel
+ cygwin testing now...
  + no longer fails in TooManyThreads or many_domain
  + no longer seems to run afoul of pthread_cond_init failures
  + no longer gets timing problems with spec/marybeth/use
+ baseline testing now...
  + no longer fails in test_module_Sort
  + no longer fails due to sorty failures
  + no longer gets glibc invalid pointer errors for v1/stencil

notes
-----
* finished taking a pass over all configurations looking for out of
  date entries
* cygwin testing has moved to full suite testing (had previously been
  examples-only due to taking too long to run on my laptop)
* chap15-16 (VM perf testing) has some threadring noise (but I think
  Thomas has redirected it to -all to avoid spamming everyone)
* removed some duplicate gdbddash entries

TRIAGE:
* noted a few weeks worth of timeouts for qthreads testing
* moved listerator tests to REGRESSIONS because they are
* noted some other timeouts, but mostly want to replace TRIAGE with jenkins
Merge pull request #30 from bradcray/bradc-triage-jul-2014

Wrapping up triage for the week
Simplify fourth part of version to just sha1.

The branch name does not add much clarity.
Add linebreak that was removed on accident...
Merge pull request #25 from thomasvandoren/git-sha1-for-build-version

Update chpl --version to use git sha1 and branch, instead of svn revision