Decouple main from ichimain

[cm-beilstein]

In order to improve modularity and ensure unit tests for high level functions such as ProcessSingleInputFile can be carried out, the main needs to be extracted and placed into a separate file.

• Step 1: separate processing functions (reading, calcuations, ...)
  • CalcAndPrintINCHIAndINCHIKEY
  • global variable: numbers_rrar
  • RepeatedlyRenumberAtomsAndRecalcINCHI
  • save_command_line
  • emit_empty_inchi
  • ProcessSingleInputFile
  • ProcessMultipleInputFiles
  • GetTheNextRecordOfInputFile
• Step 2:
  • global variable: bInterrupted
  • user_quit
  • eat_keyboard_input
  • MyHandlerRoutine
  • WasInterrupted
• Step 3:
  • Files dispstru c/h