Implement Disable/EnableLevitation script functions

Totally copied on Disable/EnableTeleporting implementation.
Thanks KittyCat!
stop weapon condition degredation (for the player) with tgm on
Merge branch 'master' into tgm
Magic effect display improvement.

Related to Bug #794.
Show the "x INT" notation for Fortify Max. Magicka.
Show "%" notation for weakness / resistance effects.
Magic Effect Display improvement.

Related to Bug #794.
Always show one decimal point precision for Fortify Max. Magicka effect.
Magic Effect Display cleanup:  Don't put spaces in percentages.
Format fix:  remove extra spaces from ranged TimesINT formatting.
MagicEffect:  Put magnitude type into ESM::MagicEffect helper.
Magic Effect:  Recognize other display types.

Fill out the list of effects which use percentage formatting.
Add in types which use Feet and level labels.
Magic Effect descriptions:  support feet / level modes.

Show proper suffixes for all magnitudes.
Drop extra 'times' symbol in 'timesInt format (not consistent
with other magnitude displays).
Cleanup in MWGui::WindowManager constructor initialzation list.

Corrected order of initialization list, and added missing
member field initializations - without this openmw crashes when
installer is interrupted and there are no valid data path
in openmw.cfg, as reported by BrotherBrick in:

https://forum.openmw.org/viewtopic.php?f=20&p=19501#p19499

Signed-off-by: Lukasz Gromanowski <lgromanowski@gmail.com>
Merge remote-tracking branch 'potatoesmaster/DisableLevitation'
Merge remote-tracking branch 'mckibbenta/tgm'
Merge remote-tracking branch 'jordan-ayers/topic/MagicEffectDisplayFormat'
Merge remote-tracking branch 'lgro/cfg_without_data_path'