Fix large cpp files issue

[ghost]

• If number of classes exceeds limit (arbitrarily chosen as 150), print .hpp and .cpp files as fragmented files to reduce size of compiled object file and reduce memory consumption during build (c++: internal compiler error #336)
• Also generate unfragmented headers for installing and usage in apps
• Introduce MultiFileBuilder and MultiFilePrinter to handle this
• Small re-org of test printers and builders
• Fix cpp doc version not being picked up correctly (C++ documentation generated with incorrect version #374). Also fix bundle doc version for cpp and python (Module bundle version missing from documentation #383)