GPXLink creation bug fix

This update includes:

• a bug fix where href of GPXLink will produce null every time when generating a GPX file.

Special thanks to @jdleung for spotting and informing regards to this bug!

Another minor update!

While this update isn't all that big, it still includes these features:

• Added Tests
• Added a direct way of saving a GPX file from GPXRoot
• Fixed missing Xcode example project in workspace
• Removal of CGFloat related methods in GPXType (Apple Watch doesn't support CGFloat and the whole project uses Double now anyways)

Minor updates

Just some new init methods in GPXParser, and other minor changes including:

• switching some init options to convenience inits
• new init options
• parser in GPXParser is now immutable

Parser enhancements

Minor updates, mostly focused on the GPXParser class.

#18 is now done, which is the main focus of this update.

• bounds, author, copyright and email tags are now parsed by the parser.
• new init method for GPXLink (with href:)

Major Update!

This update fixes bugs, as well as speed improvements to the GPX file parser.

This includes:

• Speed improvement through optimisation in GPXParser.
• Fixed bug where a file with more than one track segment will not work as expected.
• Added support for macOS and watchOS.
• Partial support of parsing metadata tag in GPX files.
• When no extensions are defined, the extensions tag is no longer written, as it is meant to be empty.
• Code cleanup

🎉Special Thanks to @lludo for cleaning up the code!

fixing 0.3.4

Fixing a fix, as a fix is required.

Bug squash

• Resolves issue #8, where track points don't work as expected.
  Thanks to @jdleung for pointing the issue out!

• The example app is also updated, to include an example for creating the a GPX file formatted as a string according to info given on the UI. This example isn't the best available, but would remain like this for now.

• GPXParser's performance is also improved and optimised. (Not good enough, more work needed)

Minor changes

• Fixed a date parsing bug
• Updated example app's text field
• Removed redundant code

Updated Example

You can now parse a GPX file from a URL textfield using example app.

The output is then shown on a tableview.

Renamed to CoreGPX

Nothing much for this release. Just a name change.