Misc compiler warning fixes.

src/api/api.cpp

@@ -146,7 +146,7 @@ unsigned int c_error(const loot::error& e) {
         extMessageStr = new char[strlen(e.what()) + 1];
         strcpy(extMessageStr, e.what());
     }
-    catch (std::bad_alloc& e) {
+    catch (std::bad_alloc& /*e*/) {
         extMessageStr = NULL;
     }
     return e.code();

src/backend/game.cpp

@@ -485,7 +485,7 @@ namespace loot {
 
         if (!loadorder.empty()) {
 
-            time_t lastTime, thisTime;
+            time_t lastTime;
             fs::path filepath = DataPath() / *loadorder.begin();
             if (!fs::exists(filepath) && fs::exists(filepath.string() + ".ghost"))
                 filepath += ".ghost";

src/backend/metadata.cpp

@@ -46,7 +46,7 @@ namespace loot {
     FormID::FormID(const std::string& sourcePlugin, const uint32_t objectID) : plugin(sourcePlugin), id(objectID) {}
 
     FormID::FormID(const std::vector<std::string>& sourcePlugins, const uint32_t formID) {
-        int index = formID >> 24;
+        unsigned int index = formID >> 24;
         id = formID & ~((uint32_t)index << 24);
 
         if (index >= sourcePlugins.size()) {

src/backend/parsers.h

@@ -531,7 +531,7 @@ namespace loot {
             boost::regex regex;
             try {
                 regex = boost::regex(filename, boost::regex::perl|boost::regex::icase);
-            } catch (boost::regex_error& e) {
+            } catch (boost::regex_error& /*e*/) {
                 BOOST_LOG_TRIVIAL(error) << "Invalid regex string:" << filename;
                 throw loot::error(loot::error::invalid_args, boost::locale::translate("Invalid regex string:").str() + " " + filename);
             }