support for editing packrat options
Merge branch 'master' of github.com:rstudio/rstudio
always return valid default packrat options
install R build tools if necessary before enabling packrat
don't auto-install packrat
short delay before prompting to install build tools
Merge branch 'master' of github.com:rstudio/rstudio
add spacing
tweak use packrat button margin
reduce size of library header
remove spurious packrat commands
handle null return from convert_from_yaml
remove CMakeLists references to packrat
option to use tcpip for postback
Merge branch 'master' of github.com:rstudio/rstudio
merge from master

Merge remote-tracking branch 'origin/master' into feature/packrat-restore-actions

Conflicts:
	src/gwt/src/org/rstudio/studio/client/packrat/Packrat.java
	src/gwt/src/org/rstudio/studio/client/packrat/model/PackratServerOperations.java
	src/gwt/src/org/rstudio/studio/client/workbench/commands/Commands.cmd.xml
	src/gwt/src/org/rstudio/studio/client/workbench/commands/Commands.java