Fix 'No preview available' showing up when it _is_ available
0.9.0 changelog
Version bump in manifest
More clear intro screen (no longer a cheatsheet) which hopefully
prevents people from running into #87.
Fixes #86 by adding the "Find:All" command

This command puts a cursor on all instances of the current selection (or
identifier in case of no selection). By default it is abound to
`Command-Shift-G`/`Ctrl-Shift-K`.
Fixes #77 by using font face and size in editbar, contextbar and editor
And properly position location of editbar info too.
Set `Ctrl-T` on Win/Linux to open the tree.
Further improved intro
Merge remote-tracking branch 'upstream/master' into zpm
Added a bunch of zpm tools to the sandbox.  Got started on the installed extensions ui.