ENH: speed,similar,borders

--HG--
branch : feature/eg/gabella_polar

NEW: function to roll 2d array

--HG--
branch : feature/eg/gabella_polar

FIX: Corrected doctest in `georef.polar2lonlatalt`

FIX: Fixed problem in `georef.polar2lonlatalt` reported in issue #22

MIN: changed load_radolan_example taking PR comments into account

MIN: further finalizing changes in the radolan composite reader, finalizing test functions, beautifying load_radolan example

MIN: reworked radolan file handling in terms of file handle, header and binary data part for better separation of operations

MIN: chnaged docstring

FIX: typo in path

ENH: added example file for loading and plotting PC/PG and RW DWD radolan data

ENH: added two example files (PC/PG and RW) to examples/data folder

ENH: introduced 'pure' rl decoding line function, introduced test functions for the radolan reader

FIX: corrected precision prefix to '1' for correct precision values

FIX: return runlength-decoded array with np.flipud() applied, changed position of clutter = None in 'read_RADOLAN_composite`

ENH: added reading of runlength encoded composites within `read_RADOLAN_composite`, added several helper functions, introduced `loaddata` switch for `read_RADOLAN_composite`, almost complete rewrite of `parse_DWD_quant_composite_header` to make handling of header token easier

Merged in heisterm/wradlib (pull request #35)

Entirely removing BUFR support from wradlib.

Merged in kaimuehlbauer/wradlib_miub (pull request #36)

FIX: header information not read correctly in `parse_DWD_quant_composite_header`

Merged in thpfaff/wradlib//feature/tp/ci (pull request #34)

Added build scripts for CI

Merged wradlib/wradlib into default

BUG: header information not read correctly in `parse_DWD_quant_composite_header`, added functionality to read gzipped files as well as uncompressed files