Update release date to 2013-09-29 and version to 5.9.10 in preparation for the planned release later today.
Update release date to 2013-09-29 and version to 5.9.10 in preparation
for the planned release later today.

Soversion bump for most PLplot libraries in preparation for the
release because of substantial backwards incompatible API changes
concerning integer to floating point line width parameters.


svn path=/trunk/; revision=12546

FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot