[platform-releng-dev] releng fixes for 6pm build

[Kim Moir <Kim_Moir@xxxxxxxxxx>]

Student's t-test value should not be
used when deviation is too small
https://bugs.eclipse.org/bugs/show_bug.cgi?id=184015

Remove the Team FTP/WebDAV feature from
build
https://bugs.eclipse.org/bugs/show_bug.cgi?id=184698

Also, the build will be using a newer
version of pde build to address.
Investigate if version suffixes can
be shortened
https://bugs.eclipse.org/bugs/show_bug.cgi?id=175714

I've run a successful test build with
the last two fixes.

Kim