fix deadlock when the reader is closed too early
Merge pull request #49 from alex85k/thread-fix

There is a deadlock if reader is closed too early
Throw if the unthinkable happens...
Fix run_test.sh to work with CXX settings like 'g++-4.8'.
Revert "Throw if the unthinkable happens..."

This reverts commit e42d72839382823f826ef2e12213abf6d7ae235a.
Problem is that g++ and clang++ throw errors. One with and one without that
line...
Bugfix: Multipolygon code was possibly accessing stale data.

In rare occasions when a multipolygon had closed ways creating an inner ring
with different tags than the area and a buffer was full and had to be resized,
the code would reference a stale location of that buffer. Fixes #47.
Refactoring of filter handling in multipolygon code.

Initialize the filter only once and simplify usage.
Avoid bogus g++ warning.

g++ reports "control reaches end of non-void function [-Wreturn-type]" because
it doesn't detect that the switch covers all cases. Fixes #29.
MinGW comaptibility