basic calendarToPdf implementation
Added colors, wekkends and holidays for calendar to print as pdf
CalendarToPdf completed except for paired bts
Issue # 15 completed. Calendar can now be printed to pdf.
Issue #15: fixed bug when bt was displayed incorrectly in case it started long enough before from date; added validation for dates when trying to print calendar with displaying error messages; modifiaed page layout for calendar in order for input form to take less space and validation messeges to display in one row; refactored code for CalendarToPdfExporter to make it cleaner; added marking today with green color on calendar's header
Merge remote-tracking branch 'upstream/master' into development
merge with upstream/development
Merge pull request #71 from Bohdan-Tereta/development

Issue #15 fixed