Implementing ScriptPlan Operations for HYRISE

Adds the possibility to write plan operations in JavaScript instead of C++
for easier prototyping. To enable this feature see the documentation and
accompanying unit tests in src/bin/units_access/ops_script.cpp. Attention
this feature is still in beta.
Merge pull request #94 from hyrise/v8

Implementing ScriptPlan Operations for HYRISE
Formatting issues in Layouter
Fixing #91 - consitency for indices
Merge branch 'master' of github.com:hyrise/hyrise
Remove unnecessary access.h include
Streamline includes in units_access/helper.cpp
Streamline includes in units_layouter
Remove <taskscheduler.h include from QueryParser.h
Remove net.h
Remove layouter.h
Remove taskscheduler.h
Actually remove layouter.h file
Add missing lib and OCD on build order
Remove memory.h
Remove unused variable assignments from PerfRegressions
Add precompiled headers to improve build speed

This adds a new first build stage "phase1" which consists
of precompiling `stdlib.hpp` in src/lib as a general header
that is then force -included into all .cpp compilations.

This severely reduces i/o seek times for the standard library
and large-ish parts of boost and should in turn drastically reduce
HYRISE compile time.
Merge pull request #97 from bastih/feature/precompiled_stdlib_header

Add precompiled headers to improve build speed
Improve performance of concatenation

When invoked with a large number of intermediate results, concatenation
was performing badly. This patch should fix such behavior.
Merge pull request #99 from bastih/feature/improve_concat_many_pcs

Improve performance of concatenation