Easy `make` for linux users

Building this gem in linux can be a little tricky cause the lack of `xbuildtool`, but we can now run `make linux` and all go smoothly.
Obviously, this only compile the binary for the current user's architecture and is meant for personal use only.
Merge pull request #387 from Iazel/patch-1

Easy `make` for linux users
Upgrade fsevents-wrapper so it can build on Xcode5
Reword the "linux" make target slightly

* Ensure that linux_v is always set, no matter what uname says.
* Use the $(shell) make function
* Remove quotes - they seem to not get interpolated for some reason.
* Use mkdir -p to make building work when the gem already has a "man"
  dir.

This fixes #406.
Merge pull request #405 from antifuchs/bump-fsevents-to-xcode5

Fix fsevents-wrapper settings so it builds on Xcode5
Fix "slave `boot` was killed", shorten backtraces

Extract command running from the `go` method. This ensures that the
process running the command never tries to re-register with the client
monitor on the Zeus side, which was what caused the "slave `boot` was
killed" messages mentioned in #410. This was originally broken by the
recursion elimination in #361 (turns out unrolling recursion is hard!).

As a pleasant side effect, this change also eliminates two more lines in
the `go` method from backtraces on commands.
Revert "We should really be using SOCK_STREAM, not SOCK_DGRAM."

This reverts commit 1ed167e80984a6dee4ca0e85be7b7ea55a70119c.
Resize SO_SNDBUF on unix sockets

This should ensure that no datagrams get truncated.
Record the zeus arguments on config.Args

This allows people to pass --log to zeus for running commands, and it
will output the trace log (and execute the right command), also.
Pass a pipe for args from zeus client to command

Instead of passing the command arguments from the zeus client to the
zeus master, and from there to the command process over their respective
sockets, create a streaming socket in the zeus client, pass that socket
over to the zeus master, have the zeus master pass it on to the command
process, and read the zero-separated arguments directly in the command.

This has a two advantages:

One, it supports unbounded numbers of arguments on Linux and OS
X (previous solutions only worked either on one or the other).

Two, it extracts all command argument handling from the zeus master -
all the master now does is pass a count and an FD from one pipe to
another.
Merge pull request #410 from antifuchs/fix-linux-command-deadlock

Fix Linux command spawning deadlock
load exect json versions or bundler blows up with already loaded other json version
Merge pull request #416 from grosser/json

load exect json versions or bundler blows up with already loaded other json version
Fixed compile error
Bump version to 0.14.0.rc1
Read json version regardless of whether it's explicitly included in Gemfile
Merge pull request #424 from swrobel/fix-json

Read json version regardless of whether it's explicitly included in Gemf...
fixes #393 and adds tests
extract mocking file existence to method
Fix version option.