Minor fix to how proxy certs are parsed (#457)

• Changed package name to phantomjs-prebuilt
• Fix for cafiles with multiple certificates

Update installer to work with windows 2.1.1 package

Update installer to PhantomJS 2.1.1
Removes dependency on npmconf

Installs PhantomJS 1.9.8

• faster install process, especially when using npm rebuild
• adds support for PHANTOMJS_PLATFORM for target platform
• security fixes
• verifies checksums of previously downloaded files

Upgrade fs-extra dependency to help with cross-file-system installs.

Minor improvements to logging, upgrade fs-extra dependency

Minor bug fixes:
Use npmconf CA settings (#293)
Use npmconf user-agent settings (#298)
fix a dangling file handle (#307)

Packaged with PhantomJS 1.9.8
Adds support for io.js
Uses fs-extra for file operations

Packaged with PhantomJS 1.9.8
Adds support for io.js