End of sprint 3

1. CalcAverVari.php: When convert to baidu Coordinate System, Calculate
average, variance values, start from the first entry imported, other
than the first entry already in database.
2. CalcAverVari.php: Ignore entries of which the lng, lat and pci are 0.
3. index.html: several UI improvements; add "Export File" button.
4. UploadData.php: The responding page for an android app to upload
data.
5. SearchRoute.php: Use hashkey array to ensure that every point
selected is unique; call
convert_sinrave_distance_to_sinrave_time_csvfile to write the results
into a specific CSV file.
6. BaseStation management pages.
7. file_helper.php: Add a function to write the "SearchRoute" results to
a specific CSV file.
8. map1.php: several display modification.
9. Playback.php: Play back how a collector collected his data.
10. GPSconvertor.php: Convert the points in a grid to the centre, other
than to the bottom-left.
11. jsMapTools.js: Move the getColor function to a global access js
file.