Fixed some typos
apidoc: Updated Doxyfile.in
swanctl: Fix Doxygen group assignment
starter: Add starter group and fix formatting of conf_parser_section_t enum

Make use of the Markdown support in recent Doxygen versions.
libvici: Add missing argument to Doxygen comment
enum: Replace þ with p in Doxygen comments
windows: Fix parameter name in Doxygen comment
swid: Fix parameter documentation in Doxygen comments
Move README to README.md so it gets evaluated as Markdown
Converted existing README to Markdown
apidoc: Include *.md and files from the complete source directory (not only src)
doc: Remove obsolete architecture description and empty known bugs list
checksum: Fix checksum generation for pki if tools are disabled
autoconf: Replace --disable-tools option with --disable-scepclient

Since using a separate option for pki this was the only tool that was still
enabled by that option.
conf: Document aikgen options
conf: Document swanctl options
conf: Document charon.*-scripts options
conf: Document load-tester.crl option
pki: Document --online option for pki --verify and all exit codes
utils: Helper macros to define overloaded macros based on number of arguments