Update MSGProvider.java
Merge pull request #8 from ahannon14/patch-1

Update MSGProvider.java
Merge branch 'master' of https://github.com/ruijiehe/trial1
Here I newed 3 static strings, you can change them when testing, no need to change every file.
Added function: check if input validate, deny null input
get local number from content provider, need not type
sending msg to url, which is declared in Login Activity, need not change when testing
extract local number from content provider
check inbox url declared in Login Activity
get local number from content provider
changed a little
Merge branch 'master' of https://github.com/ruijiehe/trial1
Amy Chattr is the app that works with my MySQL/PHP servers.  Currently only compose new and send new works properly--I'm working on getting the get conversation and get users to work.