Patch for ticket #138, #423 - Added map picker to chose dive locations,  Import GPX file from SD card

Added a Current Location Button in Mappicker
================================================================================
Changes made:
1. Added a current location button in the mappicker, which
   takes you to your current location on clicking.

Signed-off-by: Venkatesh Shukla <venkatesh.shukla.eee11@iitbhu.ac.in>


 Added date time picker to Mappicker
===============================================================================
Added datepicker and time picker (Which looks ugly) to the mappicker dialog.

Changes made:
1. Added the date time pickers to mappicker
2. Shifted the divename dialog to PickLocationMap activity to fix change of context, as pointed out by Aurelein
3. Added default dive name for current dive add.

Signed-off-by: Venkatesh Shukla <venkatesh.shukla.eee11@iitbhu.ac.in>


 Small improvements in Mappicker and Gpx Parser
================================================================================
This commit includes code improvements as suggested by Aurélien -
http://lists.hohndel.org/pipermail/subsurface/2014-March/010705.html

Changes made:
1. Code improvement suggestions incorporated
2. Marker added to the map which appears on long press
3. The marker also shows latitude and longitude on click
3. Select/Unselect all feature added in GPX import

Signed-off-by: Venkatesh Shukla <venkatesh.shukla.eee11@iitbhu.ac.in>


Ticket #423 - Import GPX file from SD card
================================================================================
Framework added for importing GPX file from SD card.
It works for dive points stored as Waypoints in the GPX file.
Dives are sent to the server as per preferences.

For importing GPX file
1. Click on add button on home screen
2. Choose the GPX file to import
3. Select the dives to import
4. Click accept

Changes made:
1. Added import option on add button in HomeActivity.java
2. Made DiveLocationLog class parcelable to be able to send and receive via intents.
3. Changed AndroidManifest.xml to include parent in activities
4. Renamed for more meaningful names
      PickLocation.java to PickLocationMap.java
      dive_loc_menu.xml to picklocation_map.xml
5. Rearranged added strings to appropriate groups
6. The strings included in languages German, French, Russian and Romanian are erased as they may not be conveying real meaning
7. Added up navigation to PickLocationMap activity
8. Changed title of PickLocationMap activity

Reported-by: marcmerlin
Signed-off-by: Venkatesh Shukla <venkatesh.shukla.eee11@iitbhu.ac.in>


Ticket #138 - For storing dive location, a map picker is added.
================================================================================
One could choose location of dive as well as time offset in minutes of the dive and store the information on server or locally as per preferences.

Changes made:
1. Added map picker option on add button in actionbar in HomeActivity.java.
2. The new strings are included in languages German, French, Russian and Romanian.
3. Changed if else ladder in HomeActivity.java to switch case for better code readability

Reported-by: henrik
Signed-off-by: Venkatesh Shukla <venkatesh.shukla.eee11@iitbhu.ac.in>