Bump version to 0.7.1

Closes #43.
typos

http://www.its-not-its.info/
https://www.stat.auckland.ac.nz/~paul/
Merge pull request #45 from jefferis/patch-1

typos
vignette uses zi4 package if available, otherwise the inconsolata package

Fixes #44.
update NEWS
Loading babel TeX package to avoid printing tilde in references

Surprisingly, this fixes the tilde introduced by texi2pdf for cross references and "et al.".

https://stat.ethz.ch/pipermail/r-devel/2012-January/063084.html

Linked from there, especially useful: http://www2.it.lut.fi/wiki/doku.php/common/latex_hints
Merge pull request #49 from yihui/vignette-tilde

Loading babel TeX package to avoid printing tilde in references
in console mode, print a \relax statement after the comment to allow using Sweave with strip.white=TRUE
Merge pull request #48 from yihui/47-Sweave-console

in console mode, print a \relax statement after the comment to allow using Sweave with strip.white=TRUE
mention strip.white in vignette
update NEWS
Bump version to 0.7.2
fix for issue 52
added a test of the new tikzAnnotate code
don't resample raster images when writing out to png
update flush annotation test and include a known good copy of the plot
Merge remote-tracking branch 'origin/master' into noresample
spacing
Merge pull request #53 from smason/master

Fixes #52: Add parameter checkstate to tikzAnnotate to allow annotating an empty plot
spacing