Pygrib

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* try to import pyproj, and if that fails try to import pyproj
from mpl_toolkits.basemap.
* reduced verbosity of grib_list.
* made grib_list more robust (prints "NOT FOUND" when there is an error
reading the value for a key).
* allow for specifying header and library directories separately
(e.g. GRIBAPI_INCDIR and GRIBAPI_LIBDIR env vars, instead of just
GRIBAPI_DIR)
* fix setup.py to reference zlib as "-lz", not "-lzlib" (issue 9).

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* added is_missing grib message method (to check if the value associated
with a key is set to the grib missing value constant).
* grib_api_version module variable contains version info for grib_api lib.
* added *_LIBDIR and *_INCDIR env vars to setup.py for more flexible
specification of library and include dir locations.
* fix bugs in handling of scale factor for radius of the earth.
* some grids use the key "projectionCentreFlag",
while some use "projectionCenterFlag". Account for
both possibilities (added to test_stere.py).
* missingvalue_int and missingvalue_float are now module variables
(not instance variables).
* raise error if no keys are specified when creating index instance.

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* only print ensemble info in __repr__ (which is called when 'print grb' is
done) when both both 'perturbationNumber' and 'typeOfEnsembleForecast' keys are
present. Fixes error on 'print grb' for ERA-interim grib files.

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* raise IOError when grib message number < 1 is accessed with message method
(instead of segfaulting, which is rude). Fixes issue 4.
* indexing open instance (iterator) with an integer key now is the same as
calling the message method (grbs.message(2) == grbs[2]).
* slicing iterator now also works (grbs[::2] returns every other grib message
in a list).
* added 'select' method to open instance for selecting grib messages based
on key/value pairs.
* added 'index' class which can be used for fast subsettting of grib files
based on specified key/value pairs (a faster alternative to 'select' method
of open instance).
* fixes for grib_api version 1.9.0 (the names of some keys changed).

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* fix bug in latlons method for space_view grids not centered
on the equator at Greenwich.
* compatibility fixes for version 1.8.0.1 of grib_api definitions
(the names of several keys changed from version 1.8.0).
* use __cinit__ to initialize C level objects, __init__ for
python level objects (instead of doing everything in __new__).

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* allow gribmessage keys to be set or accessed like attributes.
* added __dealloc__ method to gribmessage to allow for garbage collection.
Prevents out of memory errors when iterating over large numbers of grib
messages.