add beginWith matcher
update README with beginWith description
add EXPMatchers+beginWithTest
add endWith matcher
update README with endWith description
add EXPMatchers+endWithTest
fix indentation for respondTo, beginWith, endWith
undo indentation fix already done in acf328c
merge master into branch
Merge pull request #58 from peebsjs/begin-and-end-with-matchers

add beginWith and endWith matchers