STY: Reuse ThickLineTool in LineProfile
Merge pull request #374 from tonysyu/add-rank-to-bentoinfo

Add rank extensions to bento.info
BUG: Fix blitting behavior in canvastools
STY: Refactor parts of LineTool to CanvasToolBase
BUG: Clean up imports
Merge pull request #361 from ahojnnes/hough-peaks

Add hough transform peak detection
Add example for hough_peaks function
FEAT - combined API from is_local_maximum() into peak_local_max()

is_local_maximum() is a wrapper function for peak_local_max()
is_local_maximum() runs much faster (~20% of prior runtime, nearly = to peak_local_max())
All tests in .feature and .morphology subpackages pass as written with these changes.

Todo:
  * Fully document API
  * remove commented-out old algorithm in is_local_maximum()
  * add new tests for full coverage of new, more complex peak_local_max()
FEAT - Unified peak finder backend

Detailed changelist:
  * Fully documented new API for peak_local_max()
  * Removed commented-out old code for is_local_maximum()
  * Added "See also" and "Notes" to is_local_maximum() redirecting to peak_local_max()
BUG - Fixed a bug where, when `indices` = False, output was not Boolean.
BUG - Fixed a bug where the image was not properly masked for each unique label.
BUG - Now parsing all unique labels != 0 properly, and set threshold_rel=0 in is_local_maximum() wrapper.
BUG - Dtype conversion to Boolean in a new code path not included in current tests.
ENH Add imread io plugin

This relies on imread (https://github.com/luispedro/imread) which
supports a few microscopy formats otherwise hard to read (LSM and
MetaMorph STK) as well as basic ones.
RFCT Use `skimage.utils.convert` for type conversion
DOC Add myself to CONTRIBUTORS.txt
TST Remove unneeded test

Per stefanv's comment on github, this was testing functionality higher
up in skimage.io
Merge pull request #373 from luispedro/imread_io_plugin

ENH: Add imread io plugin.
BUG - `rank_order` now imported.

Also changed (peak.py):
  * Standardized documentation as requested.
  * Removed `threshold` as an optional kwarg.
  * Removed extra line break incorrect by PEP8 standards.

Also changed (watershed.py):
  * Added @deprecated decorator and import statement
doc: deprecated string and docstring formatting fixes in `is_local_maximum`