fish for Mac2.3.1

Changes

• A new fish_key_reader binary for decoding interactive keypresses.
• fish_mode_prompt has been updated to reflect the changes in the way the Vi input mode is set up, making this more reliable.
• fish_config can now properly be launched from the OS X app bundle.

Notable Fixes and Improvements

• Extra lines were sometimes inserted into the output under Windows (Cygwin and Microsoft Windows Subsystem for Linux) due to TTY timestamps not being updated.
• The string builtin's match mode now handles the combination of -rnv (match, invert and count) correctly.
• Improvements to TTY special character handling, locale handling and terminal environment variable handling.
• Work towards handling the terminal modes for external commands launched from initialisation files.
• Ease the upgrade path from fish 2.2.0 and before by warning users to restart fish if the string builtin is not available.
• type -a now syntax-colorizes function source output.
• Added completions for alsamixer, godoc, gofmt, goimports, gorename, lscpu, mkdir, modinfo, netctl-auto, poweroff, termite, udisksctl, and xz.
• Improved completions for apt, aura, git, npm, string, and suspend