Fixed Instance Status usage

    Instance Status in Instance Service Status were inconsistently
    used in the code base.  Sometime strings were used in places of
    object. Sometimes the wrong object type was used in place of
    another.  Sometimes lower-case strings were compared to
    upper-case string
    Added comments and type hints in various classes
    to prevent further issues and to aid in troubleshooting
    Changed usage of mysql to datastore in instance and task
    functions

Partially Implements: blueprint improve-instance-status
Change-Id: I3e36d4ab879073b685a0585d02a62dfe157a5b3c
Parses default configuration of an instance

The call to get the default configuration of an instance failed if the
my.cnf template has a key with no value.

Change-Id: Ib0ea6166b25ccd0e230cd97c22c419b432484c92
Closes-Bug: #1291158
Add timeout on prepare call per datastore

Reasons:
 - each datastore requires its own timeout due to amount of
   time that needed for packages to be installed and time
   that needed for start scripts.

Changes:
 - timeout option per datastore proposed.

Change-Id: I111e4d9384668ed341dab2d27f7795979dc2ceba
Implements: blueprint timeout-per-datastore
Merge "Add timeout on prepare call per datastore"
Merge "Fixed Instance Status usage"
Merge "Parses default configuration of an instance"