[FIX] Using CMAKE_FIND_PREFIX_PATH in CMakeLists.txt.

It turns out that one should use CMAKE_FIND_PREFIX_PATH instead of CMAKE_FIND_ROOT_PATH for find_package() to work.
Merge pull request #102 from holtgrewe/hotfix/cmake_find_root_path

[FIX] Using CMAKE_FIND_PREFIX_PATH in CMakeLists.txt.
[FIX] Fixing nightly build warnings in genomic_variants.cpp in MSVC.
Merge pull request #107 from holtgrewe/hotfix/mason_nightly_warning

[FIX] Fixing nightly build warnings in genomic_variants.cpp in MSVC.
[FIX] Reverting 308d5e which causes a regression with empty SWIFT pattern.

The new test in test_index_swift.cpp breaks without the patch in index_wotd.h.
Merge pull request #109 from holtgrewe/fix_regression_308d5e_master

[FIX] Reverting 308d5e which causes a regression with empty SWIFT pattern