New SnareMarch preset and updated KickPower

The snare sounds like it would be used for marching. If you can make it
brighter without making it sound funny, please do...

The kick was too dark for general purpose. Shortened it, raised it in
the frequency range and added more noise.
Merge pull request #1434 from curlymorphic/fader

updated Fader to use setHintText
Bitcrush: small improvement, also add some stuff to math & constants
Constants:
- calculate all in long double so as to improve the accuracy of our pre-calculated constants
- add some possibly useful constants: reciprocal of pi, square of pi, and reciprocal of e
Math:
- new math convenience functions: absMax, absMin
Merge pull request #1439 from diizy/master

Bitcrush: small improvement, also add some stuff to math & constants
Update FxMixer.cpp

prevent double adding of jobs
Merge pull request #1440 from LMMS/stable-1.1

Update FxMixer.cpp
More fixes (Bitcrush, Linkwitz-Riley filter)
Merge pull request #1441 from diizy/master

More fixes (Bitcrush, Linkwitz-Riley filter)
Check major/minor version before setting theme directory
Merge pull request #1442 from tresf/stable-1.1

Check major/minor version before setting theme directory
Fix scroll bar gap

Closes #1437
Bump DualFilter high cutoff to 20k

Closes #1395.
Crossover EQ initial commit, also fix bugs in LR4 filter and Fader
Merge pull request #1445 from diizy/crossovereq

Crossover EQ initial commit, also fix bugs in LR4 filter and Fader
Proposed fix for #1411 Crash on LB302 preset preview .
Merge pull request #7 from LMMS/stable-1.1

merge LMMS/lmms
Proposed fix for #1432 LB302 preset preview audio cut-off
Merge pull request #1447 from curlymorphic/1411

Proposed fix for #1411 Crash on LB302 preset preview .
Merge pull request #1433 from Sti2nd/stable-1.1

New SnareMarch preset and updated KickPower

No objections after a week, merging. -Tres
Proposed fix for #1411 Crash on LB302 preset preview .