Fix StringData::substr with single argument

Original version had an overflow bug
added unit test for BytesQuantity, and fixed some bugs #266

Also noticed that we needed to backport a bugfix for StringData::substr.

closes #266
tokumx-1.3.0-pre-
fixed maybe-uninitialized warning #266
Merge branch 'unittest-fix'
fixed a non-generic-ness in buildbot config #402
added 1.2 to buildbot config #402
lowered base port for tests to avoid ports >2^16 #402
remove DB_NOOVERWRITE from update flags #483

closes #483
Merge branch 'bugs/483'

Conflicts:
	src/mongo/db/namespace_details.cpp
Merge branch 'master' into visualization