make test position independent
Add benchmarks
compile regexp only once

Go has no regexp cache.

Compiling the regexp only once makes process name normalizations 3x faster
and amortizes on bigger loads and/or lots of threads.

benchmark                       old ns/op    new ns/op    delta
BenchmarkNormlizeProcessName        12539         3566  -71.56%
traverse directories while parsing

Use a goroutine to parse an directory entry while reading the next one.
Not using the path/filepath.Walk to avoid stat calls, sorting and call
overhead.

benchmark                       old ns/op    new ns/op    delta
BenchmarkCollect                  2631962      1747219  -33.62%
use strings.Fields() for whitespace separation

strings.Fields is faster and simple to use for splitting by consecutive
ranges of various whitespace.
Linux specific net statistics

```netstat -s``` has 32bit overflow issues on some systems.

Since Linux already provides easy to parse SNMP statistics via /proc
just provide a special implementation and build net.go along with their
tests only for non-linux systems.

As a side effect I also observed reduced memory footprint
and increased execution speed.
Merge pull request #1 from nightlyone/fast_process_iteration

Speed up process metric collection
Merge pull request #2 from nightlyone/use_strings_fields

use strings.Fields() for whitespace separation
Merge pull request #3 from nightlyone/no_netstat_on_linux

Linux specific net statistics
version 0.1.4