scan-build warning
get correct mask
Merge pull request #464 from stefan-kurtz/sk

Sk
Merge pull request #466 from Garonenur/scan-build

Scan-Build errors
add threaded compilation

concerning and closing #465
description of $cur variable fixed
make splint happy
fix (some) race conditions for tests

running the testsuite in multithreaded mode breaks some tests,
especially if run after ```make cleanup```
shredder test thread safety
more thread safe sequniq tests
fix copy paste errors for shredder tests
use apt caching in travis
Merge pull request #467 from Garonenur/travis

add threaded compilation
do not silently pick characters in wildcards
Merge pull request #472 from satta/translate

do not silently pick characters in wildcards
build uses 2 jobs on travis
Merge pull request #474 from Garonenur/travis

build uses 2 jobs on travis
Fixed incorrect behaviour when generating mutated sequence.