Cleanup pom.xml

* Add canonicalUrlBase
* Add glossaryCollection - this will not build the glossary,
  but make glossterms work and silence build warnings
* Remove profileSecurity setting, we should always use the
  default of external.

Partial-Bug: #1273135

Change-Id: I7ff5b79de2a845382335da8e779ee34e20316f87
Remove tools/validate.py

The tool is not used anymore since we use tox based gating.

Change-Id: I147cb04495fef8b2f1a5b2318b1a11b4a402dd42
Merge "Remove tools/validate.py"
Merge "Cleanup pom.xml"