database: Mark rows valid when inserted

It doesn't make sense to need to set this value outside of the database
code like I had been doing.  So when a new row is inserted mark it as
valid right away.

Signed-off-by: Anna Schumaker <schumaker.anna@gmail.com>

design/database.txt

@@ -100,9 +100,9 @@ Database: (lib/database.cpp)
 
 	template <class T>
 	unsigned int Database :: insert(T &);
-		Adds a new item to the db, returns the id of the item.
-		if DB_UNIQUE is set, check if the item already exists in the
-		DB and return it's ID instead of adding a new item.
+		Adds a new item to the db, marks it as valid, and returns the
+		id of the item.  if DB_UNIQUE is set, check if the item already
+		exists in the DB and return it's ID instead of adding a new item.
 
 	void Database :: delete(unsigned int index);
 		Mark db[index] as invalid (quick deletion).

include/database.hpp

@@ -88,6 +88,7 @@ unsigned int Database<T> :: insert(T val)
 		}
 	}
 	db.push_back(val);
+	db[_size].valid = true;
 	_size++;
 	return db.size() - 1;
 }

tests/database/database.cpp

@@ -23,7 +23,6 @@ DBTest :: DBTest()
 DBTest :: DBTest(unsigned int val)
 {
 	value = val;
-	valid = true;
 }
 
 void DBTest :: write(File &file)