CDClient cleanup and optimization (#1023)

* CDClient cleanup and optimization

- Use static function to get table name
- Remove unused GetName function
- Replace above function with a static GetTableName function
- Remove verbose comments
- Remove verbose initializers
- Remove need to specify table name when getting a table by name
- Remove unused typedef for mac and linux

* Re-add unused table

Convert tables to singletons

- Convert all CDClient tables to singletons
- Move Singleton.h to dCommon
- Reduce header clutter in CDClientManager

dDatabase/Tables/CDFeatureGatingTable.cpp

@@ -34,15 +34,6 @@ CDFeatureGatingTable::CDFeatureGatingTable(void) {
 	tableData.finalize();
 }
 
-//! Destructor
-CDFeatureGatingTable::~CDFeatureGatingTable(void) {}
-
-//! Returns the table's name
-std::string CDFeatureGatingTable::GetName(void) const {
-	return "FeatureGating";
-}
-
-//! Queries the table with a custom "where" clause
 std::vector<CDFeatureGating> CDFeatureGatingTable::Query(std::function<bool(CDFeatureGating)> predicate) {
 
 	std::vector<CDFeatureGating> data = cpplinq::from(this->entries)
@@ -62,7 +53,6 @@ bool CDFeatureGatingTable::FeatureUnlocked(const std::string& feature) const {
 	return false;
 }
 
-//! Gets all the entries in the table
 std::vector<CDFeatureGating> CDFeatureGatingTable::GetEntries(void) const {
 	return this->entries;
 }