adds color profiles/output intents and an xmp metadata stream to the document in order to be compliant with pdf/a-1b (basic). this compliance level is toggled on the builder since it will generate larger files and set to 'off/none' by default. pdf/a documents are also not able to use standard fonts so using a font when the compliance level is not none will throw.
in order to include all projects from the solution we create a new solution with an entry-point assembly which references all projects. calling dotnet pack on this single project then packages all assemblies into the produced nuget package.
also remove old glyph list references from the main project since they have moved to the fonts project.
to make the project more useful and expose more usable classes we're rearchitecting in the following way. code used to read fonts from external file formats like truetype, adobe font metrics (afm) and adobe type 1 fonts are moving to a new project which doesn't reference most of the pdf logic. the shared logic is moving to a new flat-structured project called core. this is a sort-of onion type architecture, with core being the... core, fonts being the next layer of the onion, pdfpig itself the next. this will then support additional libraries/projects as outer layers of the onion as well as releasing standalone version of the font library as pdfbox does with fontbox.
* cid cff fonts have multiple sub-fonts and multiple private dictionaries, in addition to a top level font and private dictionary. this fix uses the specific sub-dictionary when getting local subroutines on a per-glyph basis.
* chinese, japanese or korean fonts can use a ucs-2 encoding cmap for retrieving unicode values.
* add support for the additional glyph list for unicode values in true type fonts. adds nonmarkingreturn mapping to carriage return.
* makes font parsing classes static where there's no reason for them to be per-instance.
