print_doc_arg attempted to handle argments with defaults. However, it added " \\ " between them, which is actually the string " \ ".  This meant that (for example) "h IO.puts" dislayed "def puts(device \ group_leader(), item)". Changed it to escape both backslashes.
Take deps.loadpaths out of loadpaths to simplify call graph
Compile dependencies when we can in deps.check
Mark dependencies as requiring compilation every time they are fetched
Do not compile after deps.get and deps.update
Deprecate char lists in Regex
Remove support to deprecated char lists in regexes
No longer require regexes to be compiled with group information
Avoid warnings on iex suite
Make module signature writer aware of structs
Update OTP release
Use :application.ensure_all_started/1
Fix dependency compilation order
Ensure deps can run after mix deps.get
assert_receive(d) should leak

Closes #2030.
Use export_all for assert_received

We are using export_all for consistency given we can't
stop using export_all in case (moving case to the same
pattern as receive leads to warnings in the test suite).
Use export_head instead of export_all
Clean up s/t/h helpers in IEx
Implement StringIO
Use StringIO in CaptureIO

capture_io retunrs `""` instead of `nil`