Partially revert default niceShortFormat

In 9fa531d6e3a3d0291ea36ccd9f0b9f2ab1d9f11b the default niceShortFormat
was changed, which has been interpreted as a regression in #3533.

This change partially reverts the previous change and tries to strike
a balance between the old behavior and new.

Refs #3533
Only bake HABTM associations for tables that exist.

bake often guesses wrong when it comes to habtm. Only add associations
we're highly confident of. This includes tables where the foreign table
also exists.

Refs #3532
Add support for --admin to bake controller all.

I missed this when originally implementing bake controller all.

Fixes #3536
Reduce duplication in code.

This will result in all tests being skipped when any of the required
models pre-exists.
Merge pull request #1073 from cakephp/issue-3533

Partially revert default niceShortFormat

The changes introduced in 2.2 dramatically changed the output from 2.1, this change attempts to be a compromise between the 2.1 format and the 2.2 format.

Fixes #3533
Merge commit '70171f5403551b2b94b0e38830f1d4ab3ea1c27c' into initialdevelopment

# By mark_story
# Via Mark Story (1) and mark_story (1)
* commit '70171f5403551b2b94b0e38830f1d4ab3ea1c27c':
  Reduce duplication in code.
  Add support for --admin to bake controller all.
  Only bake HABTM associations for tables that exist.
  Partially revert default niceShortFormat