Add BUILD_INSTALLER option to build script. Make NO_FETCH the default.
Don't create tags for separator items.
Make installer a script option rather than environment var.
Merge pull request #199 from adobe/glenn/issue-2613

Don't create tags for separator items
Merge pull request #198 from adobe/glenn/build-script

Build script improvements
Revert "Don't create tags for separator items."

This reverts commit 4e770159b436b9ae2134b2ecfc6ec59143c4417d.
Merge pull request #201 from adobe/glenn/issue-2770

Revert "Don't create tags for separator items."