fix fetching of tarfile from NASA server

switch to urllib2 as that automatically sets a User-Agent
header, which is required to fetch a file from
data.giss.nasa.gov.
move code to https://github.com/drj11/ukmo
move canada code to https://github.com/drj11/cadoe
remove SVN keywords
accept command line arguments for gistemp2csv
document how the output filename is chosen
push output file opening into 'with' statement
remove unused local variables
add --one-header option to gistemp2csv
expand documentation for chunks()
fix splitting of seasonal anomalies
document how the --one-header option is implemented
tidy up comments and variable names in non_zonal()
scale output of gistemp2csv to be in fractional kelvin
move some files to https://github.com/ClimateCodeFoundation/ghcntool
move 2 more tools to ghcntool
typo
move popchart.py to ghcntool
add source for ERSST
note about HISTALP