Enhancements to Keyboard Functions

[spatializes]

This PR makes a few enhancements to keyboard functionality.

• Exposes the KeyToggle function for use in Robotjs.
• Adds modifiers for KeyTap and KeyToggle.
• Adds the ability to write single characters to KeyTap and KeyToggle.
• Adds keys that were missing from KeyTap to both KeyTap and KeyToggle.
• Fixes a bug I noticed in KeyTap. Seems it was not releasing the key. I used the OSX keyboard viewer to see this. As already suggested in one of the issues, I added a sleep function to fix. I did not fix this in the mouse events, but the mssleep function can be reused.

Closes #7
Closes #14

[octalmage]

Looks great, thanks a ton!! Let me test the changes then I'll merge it.

👍

[spatializes]

Awesome, no problem. Let me know if you want anything refactored or done differently. I plan to use and extend quite a bit of this library for controlling PCs with a data glove I'm working on.

[octalmage]

Wow sounds epic! Can't wait to see the project.

[octalmage]

@drquinn this is small, but could you add periods to the end of all errors? Thanks!

@maxogden does this PR line up with your projects needs?

[max-mapper]

Sorry it's hard to tell from the diff (I am not very good at objective-c and don't have time to test out this branch at the moment), but my branch is here for reference https://github.com/maxogden/robotjs/commits/keyupdown

[octalmage]

No worries! I'll check it out. I just want to avoid any conflicts.

[octalmage]

I'm just going to merge and fix the style inconsistencies.

Thanks again!

[spatializes]

Sorry about the inconsistencies. Thanks for taking care of it!