DSPManager: Save and load presets from external storage

This patch adds a "Load preset" and "Save preset" option to the
menu of DSPManager, so they:
1) Survive a wipe
2) Can be swapped as you swap headphones, without having to re-do
   all your settings

Change-Id: I67ba7482404544ca99589830599c091ceb1f3b7c

Conflicts:
	res/menu/menu.xml
	src/com/bel/android/dspmanager/activity/DSPScreen.java
[2/3] Effects: Add center frequency param to bassboost

Change-Id: Ic082790010ed9e9abaf0e3249034322234119c66

Conflicts:
	res/xml/headset_preferences.xml
	src/com/bel/android/dspmanager/service/HeadsetService.java

Conflicts:
	res/values/arrays.xml
	src/com/bel/android/dspmanager/service/HeadsetService.java
[1/3] Effects: Add a stereo widening effect

Based on self knowledge.
Aside from the filter, a HighPass method has been
added to Biquad in the DSP library

Change-Id: I5dc8afa75cdf179c71ec38359887be9a5a60d4bd

Conflicts:
	src/com/bel/android/dspmanager/service/HeadsetService.java

Conflicts:
	src/com/bel/android/dspmanager/service/HeadsetService.java
fix merge Derp

Conflicts:
	src/com/bel/android/dspmanager/service/HeadsetService.java

Change-Id: Idb85be136fb7ae48d291e1fe12b5ba95fef0529c
Control Faux123's Sound Control Kernel Modules

Preview:
http://goo.gl/PQNPdH

Allows to control Faux123's Sound Control kernel feature with
DSP Manager.

If modules are found, it will show the tab, otherwise not.

It is able to apply values, load presets and restore the
values on boot.

Supports Sound Control version 2.1, will support higher versions
once they are tested.
They can be enabled easily afterwards.

Change-Id: Idf44b0341e762cbe75bef8b586a4df4765ddcbae

Conflicts:
	res/values/strings.xml
DSPManager: Control Boeffla Sound

Change-Id: I3e5447551bab1961f2bea4241a13572ec8009368
fix a little

Change-Id: Ida1a39e6871a8229c51599d5907b34120d32b50d