v3.1.5
This release only contain minor cmake improvement:
馃敤 QOLM_VERBOSE if QOlm is main project 417559f
馃敤 Disallow in source build 0d85845
馃敤 Default build type to Release (CMAKE_BUILD_TYPE) b584c4e
馃敤 Set global property USE_FOLDERS only if QOlm is main project ab92c69
馃敤 Use standard CMAKE_INSTALL_INCLUDEDIR 53e1cff