add ability to change help text, fixes issue #291
allow function to return message
add ability to disallow specification names
update changelog
update sample condarc
explicit is better than implicit
not finding any packages to remove should result in an errror
add missing return statement
remove local variable
update behavior of explicit method in resolve module, see docstring also added new tests
add test for previously unspecified case
directory may be exist
add header to output
simplified how help function is called
allow changing help messages for update and remove commands
update changelog
reorganize code in create cli
add iterable default
remove unused functions
avoid duplicate string