[base] TokenShaper: minor incremental improvements
debian: fixes to upstart script
[base] Counter: some API cleanups
[base] TokenShaper: adapted to changes in Counter API
[http] HttpServer: code cleanup
Implements support for SO_REUSEPORT (w/o flow API yet) - closes #60.
ChangeLog update
Merge branch 'master' of github.com:xzero/x0
add support for explicitely specifying reuse_port opt in server config's listen directive.

Example:

    handler setup {
        listen bind: 0.0.0.0, port: 80, reuse_port: true
        worker [0, 1, 2, 3]
        # ...
    }

This will create 4 listener ports (one for each worker) if supported by
the kernel, but will fall back if not.
comment-fu
[base] TokenShaper: fix in resize() propagation
[base] ServerSocket: fixed inheriting SO_REUSEPORT option for clone()'d sockets
optionally install crash handler
[http] HttpServer: some small fast-path optimization for single-threaded apps, as we would schedule onto the one and only thread anyway.
[http] HttpWorker: eliminated dead code.
adding helper script to generate gnuplot graphs for benchmarks
initial attempt to save number of calls to memory manager by using free-lists.
Merge branch 'master' of github.com:xzero/x0
implements x0d bash completion. closes #65
[http] HttpServer: drop fromText().