method on Iterable to replace null elements #190
test for #190
changing Iterable.defaultNullElements implementation to use a comprehension #190
update language module for changes to string/character literal syntax
update tests for changes to string/character literal syntax
Merge branch 'master' of https://github.com/ceylon/ceylon.language into
infix

Conflicts:
	test/check.ceylon
	test/spans.ceylon
string rep of sequences changed
Merge branch 'master' of https://github.com/ceylon/ceylon.language into infix
Merge branch 'master' of https://github.com/ceylon/ceylon.language into backticks
double-backticks now used to quote interpolated expressions
update tests to use `` for quoting interpolated expressions
fix interpolated string for combined test
fix tests that were garbled up by replacing wrong chars
Merge branch 'iterable-default-for-null' of https://github.com/loicrouchon/ceylon.language