Follow official edition changes
Compatible Changes different from Official Edition
1) Remove the plugin restriction in x64 edition ( back out Bug 1165981 )
2) Restore distribution/bundles support ( back out Bug 1144127 )
Additional fixed official bugs
1) Bug 1083930 – cpu spin during large h2/spdy upload
2) Bug 890284 – Stop splitting textnodes in the XML content sink
Modified pcxFirefox special feature parameter
1) pcxfirefox.scr.timer : 3600 -> 900
2) pcxfirefox.memory.firefox.smart.dynamic.ratio : 80 -> 90
3) pcxfirefox.memory.firefox.smart.dynamic.min : 128 -> 512
