Add an email share button

[3vivekb]

This issue is blocked by #140

Replace the feedback button,

With a share button,

Please grab the code from the original modeify and use that.

I'd prefer some sort of share by a webservice, or just using gmail, otherwise we'll try to figure out how to make our own webserver.

For now we'll get share by email. If we have time, we should add a share by sms option.

[3vivekb]

I'm not sure where in the code or which commit, but the original modeify is here:
https://github.com/conveyal/modeify

[3vivekb]

• Replace Feedback with Share (and share logo similar to CarFreeAtoZ)
• Get rid of share button at the top
• Rearrange Name, Email to be at the top and copy link to the bottom
• Remove directions from the body of the email
• Don't auto copy the link till somebody clicks "Copy Link"
• Change the wording for the Copy link (maybe just say Copy and add a header that says something like "Share Trip by Link"
• Consider removing the body section especially if it is static (for space reasons).
• "A link to your trip plan will be sent to the email address specified." Or similar.

[3vivekb]

• Rebase from master

[linuxwebexpert]

Please put feedback button back and use Font Awesome Copy Clipboard icon as was shown in previous commit. We actually use the feedback button - https://www.surveymonkey.com/r/ZB63FHZ -- and have another open issue #65 to improve this feature. We do not have any issues open to remove this feature.

We cannot simply remove features without discussing the impact of those decisions.

Additionally the Share / Copy Link / Email button is top right in most web applications, not at the bottom of the page off screen where it is not visible unless you scroll down to find it, hence losing sight of your URL and the important trip details.

Comments, suggestions and thoughts appreciated.