FIX: Minor fix for vol src space
ENH run_subprocess(): warn if PATH contains a path starting with ~
Merge pull request #570 from christianmbrodbeck/subp-warn

ENH run_subprocess(): warn if PATH contains ~
Merge pull request #568 from Eric89GXL/vol-fix

FIX: Minor fix for vol src space
FIX : subplot index start at 1 in pylab (breaks on hold versions)
STY: direct doc strings for cluster_level

addresses #569
CLN: more cleaning.
Merge pull request #572 from dengemann/cluster_level_cln

STY: direct doc strings for cluster_level
WIP ENH: Resume dataset downloads with NILS code

Copy code from NILS to enable resuming downloads of sample datasets. Use the
NILS code to perform the downloading instead of the previous code.

This is just the first step in implementing resuming dataset downloads. Next
the borrowed code must be integrated with the previously used code. For
example, the progress bar isn't working now.
Code copied from NILS now uses ProgressBar
Use ftplib to resume downloads

Resuming downloads now works due to changes based on code from
fileDownloader.py, however:

* _chunk_read is now called only when first downloading a file, not when
 resuming downloads
* the progress bar doesn't work yet when resuming downloads
Remove unused code from NILS
Add update_with_increment_value() to ProgressBar

update_with_increment_value() allows updating the progress bar by giving the
size of the downloaded chunk instead of the overall amount of data downloaded.
Update progress bar during resumed download

Use a new callback function _chunk_write_() to write downloaded chunk to a
local file and update the progress bar with update_with_increment_value()
Separate ftp resume code into new function

This change makes _fetch_file easier to understand and also makes the code for
starting the file download and for resuming it more similar.
STY Remove trailing underscores in function names
STY Make attributions consistent with older code
FIX Display archive name when downloading
STY Several small changes

* Remove blank lines
* Explicit use of python types (number->int, boolean->bool) in documentation
* Remove unnecessary return statements
STY Remove blank line