material on character vectors added to mod3 of intro to R
a few small tweaks to mods 1-3 of intro to R -- ready to start writing tests
added explanation of help function to mods 1 and 2 of intro to R
made a few more tweaks to mods 1-3 of intro to r to include help function explanation
fixed merge issue -- ready to start writing tests for mods 1-3 intro to R
couple of fixes and updates to mod1 of intro to R csv file
replaced spaces with underscores in intro to r directory name to avoid headaches
bug fix, #38 `runTest.expr_identical()` has trouble with lonesome variable
Merge remote-tracking branch 'swirldev/master'