build fix
tidying up the output from CreateReleasePackage - includes delta package
sort the packages by last write date - 1.9 < 1.10 is what we need
if delta updates fail, fallback to installing without deltas
moved logic to detect version from filename to extension method
added a test to ensure you don't create a delta package using a newer base version
only build the delta between this and the last full version
version bump to 0.6.10
Merge pull request #80 from github/releases-hotfixes

Releases hotfixes