BUG: fixed typo in read_cfradial functions
+Add locations of all well-known WSR-88D stations. (Source: Weather Climate Toolkit)
+Add capability to read old nexrad-cdm archive. (Read lat,lon,alt from config)
*It is more reasonalbe to always set reference altitude to sea surface when mering multiple radars. (Change in grid_mapper.py)
BUG: fixed bug in add_field_like radar method

add_field_like method of radar would overwrite the old field's data and
metadata since a copy was not made, this correct this behavior.
ENH: location set when reading old NEXRAD files.

Reading CDM converted NEXRAD files which do not contain the
latitude, longitude and altitude will not fill these parameters
in from the known locations of the NEXRAD stations.
DOC: documented nexrad_common module
Merge pull request #137 from jjhelmus/pr_126

ENH: Location determined when reading older NEXRAD files
Merge pull request #136 from kirknorth/master

ENH: default configuration
Merge remote-tracking branch 'arm_doe/master'
STY: remove trailing whitespace in default_config.py
Merge pull request #139 from jjhelmus/master

BUG: Fixes for two minor bugs
Merge branch 'master', remote branch 'upstream/master'