more user friendly: give a usage and if the file can be opened.
build tests: copycluster, parser and stow
but don't add to them to the automatic tests
since they are manual testers.
don't build the stow test program on Windows.
stow is very unixy
eliminate subscripts warning
better discovery of libicu and building with libicu
look for the icu headers only when icu is found (ie. make CMake happy)
icalrecur.c: properly handle unsupported RSCALE calendars
icalrecur.[ch]: update RSCALE draft reference
remove config-libical.h.cmake as I can't it being used anywhere.
FindICU.cmake - fix version discovery (look in uvernum.h now)
set variables if ICU DANGI calendar is available or if using 32bit time
deal with the icalrecurtest if ICU DANGI calendar is not available
or if using 32 bit time (in this case, don't run the test at all)
FindICU.cmake - print ICU_VERSION if found
setup-travis.sh - install icu so builds test that code path too
setup-travis.sh - install icu on OSX worker machines too
icalrecur.c: fix WEEKLY recurrences:
	     - fix first occurrence when DTSTART < WKST
	     - do proper calculations when start of week a given occurs in previous year
run the icalrecur_test without the -r option always
run the icalrecur_test with the -r option only if libicu is available
icalrecur_test - add regression test for issue83
ReleaseNotes.txt - mention issue83 is fixed
issue177: CalDAV attachments as in draft-daboo-caldav-attachments