net: networking optimizations

features:
- early connection
- memory cache
- caching of redirection
- request queue priority
- closing unused sockets
- SHUTR
- fin aggregation
- object prefetch
- dns host name prioritization

Change-Id: Ief90b8206ba48115eaeb12d554424d65f36427ac
net: fix preconnect memory leak

Release memory allocated in network
stack while preconnecting to a new host

(cherry picked from commit b29650c5de619dcdb73f7c5eea0e6524fc6246dd)

Change-Id: I69441be80923a06c835165a4eadda190ef11759c
CRs-Fixed: 392433
base: fix c++11 narrowing

Summary:
The best fix for this narrowing
violation is to use static casting

Test Plan: verified

Reviewers: randall.rushing, synergy

Reviewed By: synergy

Differential Revision: http://review.codefirex.com/D652