Update installer variables on Windows, update Qt5 path

This should update the master branch to use "DB Browser
for SQLite" naming, and fix the problem with the
uninstaller not showing up in Add/Remove programs on
Windows (issue #742)

src/sqlite.h

@@ -4,7 +4,11 @@
 #ifdef ENABLE_SQLCIPHER
     #define SQLITE_TEMP_STORE 2
     #define SQLITE_HAS_CODEC
+#ifdef Q_OS_WIN32
+    #include <sqlite3.h>
+#else
     #include <sqlcipher/sqlite3.h>
+#endif
 #else
     #include <sqlite3.h>
 #endif