ENH: Make plot_displacements more flexible; change default arrow appearance.
CLN/PERF: Do not import matplotlib at the module level.
Merge pull request #112 from danielballan/no-mpl-import

CLN/PERF: Do not import matplotlib at the module level.
CLN: On first run of FFTW, print info statement instead of ugly warning. Also fix typo.
Merge pull request #115 from danielballan/fftw-message

CLN: Change info on first run of FFTW.
FIX: Fix typo introducing in #112 mpl cleanup.
Merge pull request #117 from danielballan/fix-mpl-typo

FIX: Fix typo introducing in #112 mpl cleanup.
ENH: annotate features in multiple colors

Conflicts:
	trackpy/plots.py

removed white spaces

Conflicts:
	trackpy/plots.py

finished implementing the ability to section particles into different colors in annotate plot

cleanups
Merge pull request #104 from RebeccaWPerry/master

annotate with two different colors based on threshold
CLN: Remove stray debugging print statement.
Merge pull request #119 from danielballan/remove-stray-print

CLN: Remove stray debugging print statement.
FIX/ENH: Allow locate to invert float images by assuming normalization=1.
Merge pull request #118 from danielballan/allow-invert-float-images

FIX/ENH: Allow locate to invert float images (assume normalization)
RLS: Version 0.2.1
Merge pull request #120 from danielballan/rls-0.2.1

RLS: Version 0.2.1
DOC/BLD: Fix setup.py for ReadTheDocs.
Merge pull request #121 from danielballan/fix-readthedocs

Fix readthedocs
DOC: Update README with scikit-image, pip installation.
DOC: Add reminder to update version string in docs
DOC: Made beginner instructions gentler