Removed unused code and moved Btx0 to new branch
Refactor code to implement MultiImport
XML implementation of MultiImport

* Npck.cs: Basic template for MultiImport
* Program.cs: Implemented MultiImport method.
* ninoimager.sln, ninoimager.csproj: Bump version
Reimplemented Importer with Strategy Pattern
Implemented keep original settings in Importer.

Trying to import a new image keeping original settings when
there is not palette (and image) in the original pack now give
error. It makes no sense to continue importing in that case since
in-game it would use another palette (and image) files.
Implemented Import background image sharing palette
Prints program arguments and works without MultiImport xml args
Reimplemented Mapping with Strategy pattern
Implemented Match Mapping algorithm

Required to import sharing image file.
Implemented share image importer mode
Fixed bug writing palette and image files when it was shared
Fix assignment reference instead of cloning variable
Minor changes with MultiImport mode

* Safety checks (if images to import do exist)
* Prints messages if successfully
* Added imported images to the list
NSCR files must have PaletteMode set to 256/1 if they share image file
Implement importing images sharing image and palette and keeping original settings.

* Importer.cs: Ommit NSCR files encoded
Missing GetHashCode method.
Implemented OAM class.
Renamed OAM to Obj and finished its implementation

OAM (Object Attribute Memory) is the place in the RAM
where the Objects are. Objects are moveable sprites.
More info at GBATEK.
Factory method to create Objects
Frame implementation