Preventing a crash when saving an item with a missing processor and a parameter.
Now writing all parameters rather than only those not with default values (debatable which we want to do).
Now properly remapping MGEffectProcessor to EffectProcessor.
PipelineTool now knows to use StringToColorConverter for Color type properties.
Added folder-picker for OutputDir and IntermediateDir project properties.
Merge pull request #2501 from SickheadGames/PipelineFix2

Fix crash saving a missing processor, added folder picker for output/int directories.