Merge pull request #579 from MrMarc/master

Comments in PWX files not visible in RideFile Tags
Metric Histogram Plot

Update to the histogram plot to now plot long term metrics.
It enables you to plot distribution of say, Intensity Factor
for a season or cycle.

You can select the y-axis metric too, so rather than just
plotting duration you could plot say, TSS accumulated for
different ride intensities.

Fixes #560
Enabled progress translation in PowerTap download
Updated spanish translation
Notes (<cmt/>) from PWX files not added as RideFile tags...
Merge branch 'master' of github.com:GoldenCheetah/GoldenCheetah
Fix array bound SEGV

.. double to int conversion rounded up and caused an
   array bounds segv. just added 1 to the initial resize
   of the array to avoid.

.. annoying since I performed considerable testing of the
   metric histogram on Mac, but this crashed almost immediately
   on Linux. Bah.
Metric Distribution

Show BlankState when no results for date selection.