Fix parsing arguments with spacing

[addisonElliott]

Fixes issue #11.

Uses different approach from #56. When going through each file, if the file contains a space (meaning multiple arguments) and we're not on Windows, then it will attempt to use the following method to get the correct arguments.

It reads all lines from proc//cmdline. This contains the command used where each argument is separated by a NUL (0x00) character rather than spaces. So this means any spaces that are within the arguments themselves will be ignored.

Some particular notes:

• I couldn't find any references, but I believe /proc//cmdline is widely supported by all *nixes. This may be worth investigating to be sure.
• /proc//cmdline presents itself as a file but is probably stored in memory somewhere. Thus, I believe this approach should be fast to read since there is no calls to disk.

Interested in input, but I believe this method will be faster than #56 because in one file read it knows what the correct command arguments are rather than trying all combinations.

Credit goes to @moos because I basically used his test from PR and modified to get it working. Quite brilliant actually!

[addisonElliott]

@herve-g Can you try out this code if you get a chance? It should resolve your issue.

Also, I am interested to see if my PR slows things down. In theory, I don't think so but it can't hurt to be sure.

[addisonElliott]

/proc//cmdline does not work for OS X. Will need to do additional research.

Plus side is that this is working for Linux systems?