Provides a large more easily readable grid for file browsing using
`ivy'. When `avy' is installed, commands for fast avy navigation
are available to the user, as well. Heavily inspired by
LustyExplorer:

https://www.emacswiki.org/emacs/LustyExplorer

Known Bugs:

When the number of candidates don't fit into the ivy-explorer
window, moving down along the grid can change the order of elements
when new candidates get displayed. This can change the column the
user is currently in while moving vertically down or up. Although
this is a bit confusing the correct candidate gets selected.
Patches welcome!