Limits and options

Some polish added to the extension:

• New setting in Safari Preferences (under Extensions) to open tabs in foreground (slower opening is expected)
• New setting to set a limit on tabs to remember, to prevent potential memory issues

First release

Stable enough to not be called beta, but a few things occasionally misbehave.

Currently, the following improvements would be nice:

• Sometimes, the tab bar gets hidden when only one tab is open. Cmd+Shift+T is reserved for hiding and showing the tab bar.
• Add a way to prevent reopening of a tab if the same URL is open in another tab.
• Add a limit to number of saved URLs to prevent memory leaks in long browsing sessions. Purge first-in contents of the array as it grows.
• Extension malfunctions if tab reopened and closed rapidly.