Moved history code into its own source file.
New setting for history file control. Replaces 'persist_history'.
New 'history_ignore_space' setting similar to Bash's 'ignorespace'.
Tidied 'clink set' output.
Added support to control history duplicates (fixes #186).
Removed premake4.lua shim generation.
Fixes MinGW compile warnings.
New option to control how newline chars are pasted to the line.
Ctrl-L now scrolls last line to the top of the window (Fixes #229).
Less destructive clear_screen() implementation.