added isRoshHodesh & isChanukkah functions to HebrewDate class
added isErebShabbat function to HebrewDate class
added isErebYomTob function to HebrewDate class
implemented BeginTalUmatar function
implemented additional HebrewDate functions and aliases.  TODO: add tests, bypass aliases in tests
bypassed aliased in HebrewDate#occasions
fixed tests based on new HebrewDate functions