Clarify database migration mention in upgrade docs

Goes some way to addressing the issues mentioned in
http://markmail.org/message/im6xt2fw5xewgffc
Typo and fix exit status
Added format.
Generally disable spellcheck quality check

Fixes bug 2997.
Typos and cleanup: apply styleguide rules for docstrings
Docs: Minor enhacements in API docs
Added meta tags and view port

    Charset meta tags before title tag (https://github.com/h5bp/html5-boilerplate/blob/master/doc/html.md#the-order-of-meta-tags-and-title)
    X-UA-Compatible meta tag (https://github.com/h5bp/html5-boilerplate/blob/master/doc/html.md#x-ua-compatible)
    Added Mobile viewport
API: Add filtering using field lookups to UnitResource

* Units are only listed when a filter is provided.
* Filter by state allows using human-readable names: fuzzy, translated...
* Also expand UnitResource docs to document this feature.

Fix bug 2982
API: Add UserResource resource and docs

Fix bug 2959
API: Add statistics to UserResource

Fix bug 2960
API: Add UserObjectsOnlyAuthorization

This will allow to forbid access to User resources that belong to other users

Fix bug 2958
Docs: Cleanups and clarifications on Fabric docs
Fixes: Escape DB name and fix condition on if clause
Fix bug 2079

Additional option was added to search form.
If "Exact Match" option is checked we search in Exact Match Mode.

There are two search types:

  * normal search: uses indexer if available, falls back to DB search if
    not available
  * exact search: uses DB search (case-sensitive query: LIKE "%TEXT%")
Small refactoring
Improved readability
Removed unnecessary assignment
No comma after the last object member
Log messages instead of using print

Also cleanup to fix indentation

Fix bug 2928
Fix some typos, make readability improvements