Quick & Dirty Firefox fixes

Self-note for firefox tweaks on a new install:

Improve page loading by increasing pipelining:
about:config
network.http.pipelining = true
network.http.proxy.pipelining = true
network.http.pipelining.maxrequests = 15
New-> Integer
nglayout.initialpaint.delay =0

Stop loading pages in background:
network.prefetch-next = false