use rendered height rather than math to compute call frame panel height
Merge pull request #35 from rstudio/bugs/callstack

Use rendered height rather than math to compute call frame panel height
compatiblity with Rtools 3.1
position execution arrow proportionally with font
Merge pull request #36 from rstudio/bugs/callstack

Position execution arrow proportionally with font
allow for empty monitor events
option to enable/disable packages pane
catch exceptions from invalid seach terms
option to use gwt emulated stack mode
enable emulated stack via query parameter
allow newlines when logging to stderr
remove unused show environment tab setting
add environment variable for disabling packages pane