[Qt] don't regenerate autostart link on every client startup

- allows users to add additional paramaters via the autostart link
- related to #2197
Update configure.ac

Added ubuntu 13.10 and libboost1.54-all-dev incompatibility instruction to the existing no boost_sleep warning.
Update build-unix.md

Added incompatibility and instruction regarding Ubuntu 13.10 and libboost1.54-all-dev
Make gitian builds consistent across platforms

Change Linux deps to use a zip archive rather than a gzipped tarball to
match win32
Rename Linux descriptor to gitian-linux.yml to match win32
Added automake to the macports depdency list as it was required to complete the autogen.sh step as it required aclocal (which isn't included in recent versions of xcode).
Merge pull request #3546

f4e72bf Make gitian builds consistent across platforms (Micha)
Merge pull request #3547

8d31e61 Added automake to the macports depdency list as it was required to complete the autogen.sh step as it required aclocal (which isn't included in recent versions of xcode). (Scott Willeke)
Merge pull request #3542

69843c8 Update build-unix.md (Christopher Latham)
720731d Update configure.ac (Christopher Latham)
Merge pull request #3512

04aa828 [Qt] don't regenerate autostart link on every client startup (Philip Kaufmann)
Move only: extract WriteChainState and UpdatedTip from SetBestChain.
Prepare block connection logic for headers-first.

This changes the block processing logic from "try to atomically switch
to a new block" to a continuous "(dis)connect a block, aiming for the
assumed best chain".

This means the smallest atomic operations on the chainstate become
individual block connections or disconnections, instead of entire
reorganizations. It may mean that we try to reorganize to one block,
fail, and rereorganize again to the old block. This is slower, but
doesn't require unbounded RAM.

It also means that a ConnectBlock which fails may be no longer called
from the ProcessBlock which knows which node sent it. To deal with that,
a mapBlockSource is kept, and invalid blocks cause asynchronous "reject"
messages and banning (if necessary).
Per-peer block download tracking and stalled download detection.

Keep track of which block is being requested (and to be requested) from
each peer, and limit the number of blocks in-flight per peer. In addition,
detect stalled downloads, and disconnect if they persist for too long.

This means blocks are never requested twice, and should eliminate duplicate
downloads during synchronization.
Limit the number of orphan blocks

In case the total number of orphan blocks in memory exceeds a limit
(currently set to 750), a random orphan block (which is not
depended on by another orphan block) is dropped. This means it will
need to be downloaded again, but it won't consume memory until then.