* Implemented encoding of 16 bits per pixel bitmaps
* Add unit tests for 16 bit encoding and Bgra5551 conversion
* Add additional Bgra5551 pixel conversion tests
* Add Bgra5551 tests for Short2/4 and HalfVector2/4
* Use scaled vector conversion
* Bitmap encoder will now write a V3 header as default.
Introduces a new encoder option `SupportTransparency`: With this option a V4 header will be written with BITFIELDS compression.
* Add 4 and 16 bit images to the Identify test
* Add some useful links for bitmap documentation
* Add 32 bpp images to the Identify test
* Added further information on what will change for the encoder, if SupportTransparency is used.
* Added support for OS/2 version 2 bitmaps
* throw NotSupportedException, if the file header type is not BM
* renamed Os2v2 to Os2v2Size
* Added BmpThrowHelper similar to the JpegThrowHelper
* decoding bitmaps with Bitfields masks
* added testcases for Bitfields bitmaps
* added parsing of the complete bitmap V4 header to get the color masks infos for the BITFIELDS compression
* writing now explicitly a Bitamp v3 header (40 bytes)
* added test image for issue #735
* fixed rescaling 5-bit / 6-bit to 0 - 255 range
* BitmapEncoder now writes BMP v4 header
* using MemoryMarshal.Cast to simplify parsing v4 header
* added testcases for bitmap v3, v4, v5
* Bitmap encoder writes again V3 header instead of V4. Additional fields for V4 are zero anyway.
* added parsing of special case for 56 bytes headers
* using the alpha mask in ReadRgb32BitFields() when its present
* added support for bitmasks greater then 8 bits per channel
* using MagickReferenceDecoder reference decoder for the test with 10 bits pixel masks
* changed bitmap constants to hex
* added enum for the bitmap info header type
* added support for 52 bytes header (same as 56 bytes without the alpha mask)
* clarified comment with difference between imagesharp and magick decoder for Rgba321010102
* BmpEncoder now writes a V4 info header and uses BITFIELDS compression
* workaround for issue that the decoder does not decode the alpha channel correctly: For V3 bitmaps, the alpha channel will be ignored during encoding
* Fix#732