Theme: Show the stringified app version rather than the major version.

This was a regression, we changed that by accident in 1.6.0.

(cherry picked from commit 760ecd71fc48c9d8a3e825273bcc325b35c4be65)
Fix a possible crash caused by a dangling pointer
FolderWizard: Get folder map from FolderMan rather than store locally.

If the Folder::Map object is kept locally in the wizard, changes to
the map are not reflected there, as they happen when signing out.
This fixes bug #1875
Account: Add a scoped pointer to the ownCloud theme.
folderman: make escapeAlias public as its now used in accountmigrator.
cfg migration: Add a account migrator class.
ownCloud Theme: Implement appName() and appNameGUI().
Account: Add a wasMigrated flag.

If an account in a branded client was migrated from a former ownCloud
configuration, the method wasMigrated() will return true.
FolderMan: Migrate folderlist if no folder definitions can be found

and the account indicates that it was migrated. In that case,
read the folder definitions from the ownCloud config directory.
Account: Read settings from ownCloud config if no branded exists.

If there is not yet a config for a branded client, but one for the
"normal" client targetting the same URL, it will be migrated.
Account: Added missing include statement.
AccountMigrator: Do not inherit from QObject as it is not needed yet.

As requested by Danimos review.
Add missing cmakedefine for HAVE_ASPRINTF and minor cleanup.

Fixes windows build.