iedit layer, fixes

• New contrib layer: iedit. This is an experimental layer that is aimed to replace the edition feature of auto-highlight-symbol.
• New key binding to switch to another frame: SPC w o (thanks to danielwuz)
• Fix erroneous key bindings for Paradox in documentation (thanks to rphillips)
• Great new introduction in readme (thanks to chrisbarrett)
• Fix and # with auto-highlight-symbol. Now pressing correctly goes to the next occurrence and # to the previous occurrence.
• Fix window-resize micro-state which was triggered for no reason.
• Fix helm-resume by rebinding it to SPC h l (mnemonic for helm last).