Add embark-tools

A collection of embark-related tools (currently implementations of
embark anywhere and nano embark)
Update Readme.rst
Add sand indicator and allow enabling/disabling all tools
Update readme
Fix crash with child screens (e.g. saving a macro)
Add sticky (equivalent of tweak stable-cursor)
Display embark label on all 5 map pages
sticky: Fix handling of rapid input
Fix embark sidebar updating
OS X Console: Implement back/forward one word escape sequences
Migrate esc-b/f sequences to Linux
Implement extended arrow key sequences
Merge branch 'console-move-word' into console-move-word-linux
Linux: Extended back/forward word sequences
Added a way to change the mod install directory (and changed the default to hack/mods) and added simpler way to add to init.lua
Add embark-tools settings interface
New tweak: confirm-embark

Adds a confirmation when selecting [e]mbark on the "prepare carefully" screen.
Suggested in multiple threads on forums.
tweak confirm-embark fixes

* Added a display of the total embark points remaining, for convenience
* Made 'esc' work by interposing key_conflict as well
* Rearranged to look more like DF's confirmations
confirm-embark: Make esc work again
Use INTERPOSE_NEXT in key_conflict

See comment on 0a1d87c09f418c8c9075083bb207d91c6185628d