Updated position tracking

- created calcDistance utility function
- when user moves outside 5km, ask user for confirmation before updating
start location and performing new search
- organized shared variable declarations
- error handling for direction search
Added Icon

Added icon with multiple resolutions for each platform
Addded ios webclip icons

- added icons to show for ios webclips
- moved icon source files to correct folder
Locked PhoneGap plugin versions

Added explicit version numbers to PhoneGap plugins to prevent automatic
updating in the future
Revert "Addded ios webclip icons"

This reverts commit 6fa90bc7b3b635d72e58b4b8d1097a9a218ca28c.
Added ios webclip icons

- added images to image folder
- moved icon source files to proper folder
Added ios webclip icons

- added necessary code to <head> in index.html