Update makeNamespace code for R 3.0.2

Note that there are no substantive changes, but now it's taken directly
from the formatted source.
Update comment to properly reflect R 3.0
check_cran: display message when finished checking package
Update NEWS
check_cran: more informative message for missing source
new parameter args to build_win, passed to build
add NEWS
don't import deprecated text_content function
explicitly specify user agent when querying user name and ref for pull request in install_github
add NEWS
Merge pull request #423 from krlmlr/405-github-pull-forbidden

Explicitly specify user agent when querying user name and ref for pull request in install_github
Merge remote-tracking branch 'hadley/master' into build_win-args

Conflicts:
	NEWS.md

Reconciled.
Merge remote-tracking branch 'hadley/master' into text_content
Don't ignore RStudio project file.
Also update to use devtools
Add add_build_ignore
Implement add_travis()
Implement add_rstudio_project()
Add rstudio argument to create().
Make functions more chatty
More advice in add_travis()
Don't save/load workspace for packages