Break out different import/export formats

Extract iCal and pcal import/export routines into separate files. This
reduces complexity of the super huge "io.c" source file and makes it
easier to follow changes that affect the iCal and pcal routines only
(commits affecting both formats are very uncommon).

Before:

    $ wc -l src/io.c
    2938 src/io.c

After:

    $ wc -l src/{io,ical,pcal}.c
     1445 src/io.c
     1263 src/ical.c
      317 src/pcal.c
     3025 total

Signed-off-by: Lukas Fleischer <calcurse@cryptocrack.de>

0 files changed, 0 insertions, 0 deletions