Bug # 1172337 - Consolidated common files to "common" directory.

Consolidated XML files, and their dependencies, used by both the install and
compute admin guides in the "common" folder. Where a file was identified
as being used by only one of the two guides it was moved to that guide.

Change-Id: I2b6a8e711f08883a1565d671b8292c9ce5778237
Merge "Bug # 1172337 - Consolidated common files to "common" directory."