Update and improve documentation

[bitsgalore]

Add/update the following:

• Support for CD-i and mixed mode discs
• Update format description of batch manifest:
  • removed carrierType column
  • added mixedMode column
  • added cdInteractive column
• Updated interface, removal of CarrierType entry
• Removal of Increase Previous button, new behaviour of Use Previous (PPN) button (i.e. this now also increases the VolumeNumber value from the last entered value).
• startOnFinalise option
• explain log lines that are displayed upon submitting a carrier (e.g. 10 - 378374036 - Na klar!. Luister- en kijkboxen, 6 vwo (3))
• explain file version.txt in batch with Iromlab version
• document socket API

[bitsgalore]

All done.