CHE-669 Make terminal easier to find

[skabashnyuk]

This is an autogenerated issue.
Original: https://jira.codenvycorp.com/browse/CHE-669
Reporter: Stévan Le Meur
Description: At this moment, it is really difficult to know how to get a terminal in a machine.

We have two wuick things to do to improve that.

1-Change the get terminal icon
Instead of the "+" button let's use this button:

!Screen Shot 2016-03-01 at 14.39.49.png!

2-Add an entry in Run menu to get a terminal
At first line:
!Screen Shot 2016-03-01 at 15.00.21.png!
add "Terminal" with terminal icon that we have in the console panel.
then add a separator

[ddementieva]

Fixed by b1fbe7f