Removed valueHint from effect parameter and turn all values form QVariant into double
Merge remote-tracking branch 'upstream/master' into rm_value_hint

Conflicts:
	src/effects/effectmanifestparameter.h
	src/effects/effectparameter.cpp
	src/effects/effectparameter.h
	src/effects/effectparameterslot.cpp
	src/effects/effectparameterslot.h
	src/effects/native/butterworth8eqeffect.cpp
Added ahelper function for retreving bool and int. Inline these functions.
Add another ValueHint for enumerations
Add a list of options for enumeration parameters to EffectManifestParameter
Add a special case for EffectManifestParameter::VALUE_ENUMERATION
Make getOptions() method const because it is being called on a const object
Set the number of states for each EffectButtonParameterSlot
Add special treatment for EffectManifestParameter::VALUE_ENUMERATION (wrap around the values)
Add getManifest() method to EffectParameterSlotBase
Add a new widget derived from WPushButton which displays a QMenu with available options when right clicking the button
Add WEffectPushButton to depends.py
Write a new method for parsing an EffectPushButton skin node
Introduce a list which is responsible for remapping indices of active parameters
Use the remapping provided by the EffectManifest
Add information about active button parameters inside EffectManifest
Use the mapping provided by the EffectManifest when asking for a button parameter
Remove the hard coded mapping function from EffectManifest's constructor
Replace getParameter and getButtonParameter methods with getParameterForSlot and getButtonParameterForSlot
Use the newly added methods for retrieving the appropriate EffectParameter inside loadEffect method