Release pdfSweep 2.0.6

This is the first release of pdfSweep for a while, but we`ve been busy and have fixed two bugs:

in .NET pdfSweep could cause an exception when dealing with images using an indexed color space, where it would try to fill the redacted area with the incorrect color. It will now pick a color that exists within the palette.
editing of content streams could cause Acrobat Reader to fail when reading the document.