= Idea =

Quiet often while working with Redis the user might feel a need to
have counters per event. Events could obey some hierarchy, i.e.

    user/1/newPosts
    user/2/newPosts
    ...
    user/n/newPosts

    user/1/to-user/2/messages
    user/3/to-user/1/messages

Would be useful if redis-browser could somehow represent the data from
all of these keys in some kind of a table view.

= Realization =

MS Excel, OS X Numbers, Libreoffice alternative - these are all good
examples of software which can pivot, sort, filter, slice and dice table
data (even hierarchial data).

This commit addresses an Export to CSV format to be consumed by such
apps.

= Implementation =

"Export CSV" is an extra button in the top-right corner of the header.
When clicked, opens a form similar to "Configure Redis Connection" form.
From there the user is able to choose:

* Include keys - keys to include in the output as per Redis KEYS man.
* Exclude keys pattern - regex which excludes the keys from the output.
* Filename - a file with that name will be downloaded if export was good.

Only Redis String datatype is supported for exported keys for a reason -
the keys and values are extracted to be opened in MS Excel, Libreoffice
alternative or OS X Numbers.

Keys are broken down in separate CSV fields the same way the keys are
broken down into a hierarchy view on the lefthand side of the UI - by
delimiter [:/]

= Configuration =

"Exclude keys pattern" comes from config.yml. A connection now has an
optional parameter - exclude_pattern. Example

    exclude_pattern: "^.+/total/.+$"

"Include keys" - if no key is selected from the tree on the left hand
side - "*", otherwise - the selected key.

Remove hiddenElement after 5 seconds

Hide $scope.export.error on form close