Remove caTools dependency

Instead, use base64 encoding function from httpuv
Add custom version of selectize.js to work around Firefox bug

This is a workaround for issue #550. This version is based on selectize version 0.9.1.
Merge pull request #553 from wch/hidden-selectize

Add custom version of selectize.js to work around Firefox bug
Bump version to 0.10.1
Merge pull request #552 from rstudio/no-catools

Remove caTools dependency
Merge tag 'v/0/10/1'

Shiny 0.10.1 released to CRAN
Bump to development version number
a consequence of PR #552 is R 3.0.0

those who still wish to install shiny under R 2.15.x may take a look at these instructions: https://gist.github.com/yihui/43a68d811dade1d9e828