ganeti_errors: Remove race condition test.

refs #14091
Add LowerCaseCharField to fix some db issues.

refs #14103
Update models to use LowerCaseCharField for hostname

refs #14103
Update LowerCaseCharField to subclass proper CharField

Previously it was improperly subclassing the form version of the charfield.

refs #14103
Add south introspection rule for LowerCaseCharField

refs #14103
Migrations: remove the testmodel table from schema

refs #14133
Migrations: remove the testmodel table from schema

refs #14133
SchemaMigration: lowercase all hostname fields

This migration changes all the hostname fields from CharFields to custom
LowerCaseCharField. This should prevent discrepancies between the RAPI
and the GWM Database.

refs #14103
DataMigration: Update all hostnames in db to lowercase

refs #14103
Merge branch 'bug/14091' into release/0.10.2

* bug/14091:
  ganeti_errors: Remove race condition test.
Merge branch 'bug/14133' into release/0.10.2

* bug/14133:
  Migrations: remove the testmodel table from schema
Merge branch 'bug/14103' into release/0.10.2

* bug/14103:
  DataMigration: Update all hostnames in db to lowercase
  SchemaMigration: lowercase all hostname fields
  Migrations: remove the testmodel table from schema
  Add south introspection rule for LowerCaseCharField
  Update LowerCaseCharField to subclass proper CharField
  Update models to use LowerCaseCharField for hostname
  Add LowerCaseCharField to fix some db issues.