add analyze and server_benchmark feature

--analyze uses malt to trace the benchmarks behavior. It uses the run
loop but the obtained results are not stored

Benchmark.server_benchmark is used if only a server is started for
each allocator and clients are used to measure its performance in the run loop.
If server_benchmark is set to True the cmds are run with the system default
allocator.

Misc changes:

* The global environment is no longer changed. Instead a custom env dict
is passed to suprocesses containing LD_PRELOAD.

* Failing cmds no longer skip the whole benchmark instead they now skip the
malfunctioning allocator.

* Fix default title in plot_single_arg

an analyse run are not stored

1 files changed, 1 insertions, 1 deletions

diff --git a/doc/Benchmarks.md b/doc/Benchmarks.md
index 4ab0c02..4aeb8a4 100644
--- a/doc/Benchmarks.md
+++ b/doc/Benchmarks.md
@@ -127,7 +127,7 @@ for number_of_runs
 
 #### run hooks
 
-* `preallocator_hook((alloc_name, alloc_definition), current_run, verbose)` is called
+* `preallocator_hook((alloc_name, alloc_definition), current_run, environment, verbose)` is called
 	if available once per allocator before any command is executed. This hook may
 	be useful if you want to prepare stuff for each allocator. The mysql benchmark
 	uses this hook to start the mysql server with the current allocator.