Fix clang compilation
Add unistd.h to main, needed for dup
Use StringView in write_debug
Use StringView in UserInterface and NCursesUI
Fix Option destructor that was not virtual
file.cc: try more portable use of struct stat::st_mtime
Replace some typedefs with usings
Add support for non-scrolling fifo buffers
Add command aliases in command info

Fixes #101
Add a -alias switch to the def command for defining an alias

Fixes #100
Paragraph selection selects next paragraph when on previous end
minor style tweak
Wrap command completion containing spaces, semicolons or quotes in double quotes
Complete option values with the current value of the option

Fixes #32
Use c++ code for 'gf' command rather than running a user :edit command
Add '$' for keeping selections that passes a shell command

'$' pipes each selections through a given shell command, and
only keeps the one that have an exit code of 0

Fixes #36
Document the '.' command in README
Use fifo buffers for git-tools command output
Refactor LineAndColumn coordinates

BufferCoord -> ByteCoord
DisplayCoord -> CharCoord

Moved their definition along with LineAndColumn into coord.hh
Improve error reporting when parsing commands

*debug* will contain line and column informations along
with the responsible command name.