Use setuptools to install Python modules

Instead of using relative imports, add support for installing the config
and db Python modules to a proper location using setuptools. Change all
git-interface scripts to access those modules from the search path.

Signed-off-by: Lukas Fleischer <lfleischer@archlinux.org>

aurweb/db.py

@@ -0,0 +1,51 @@
+import mysql.connector
+import sqlite3
+
+import aurweb.config
+
+
+class Connection:
+    _conn = None
+    _paramstyle = None
+
+    def __init__(self):
+        aur_db_backend = aurweb.config.get('database', 'backend')
+
+        if aur_db_backend == 'mysql':
+            aur_db_host = aurweb.config.get('database', 'host')
+            aur_db_name = aurweb.config.get('database', 'name')
+            aur_db_user = aurweb.config.get('database', 'user')
+            aur_db_pass = aurweb.config.get('database', 'password')
+            aur_db_socket = aurweb.config.get('database', 'socket')
+            self._conn = mysql.connector.connect(host=aur_db_host,
+                                                 user=aur_db_user,
+                                                 passwd=aur_db_pass,
+                                                 db=aur_db_name,
+                                                 unix_socket=aur_db_socket,
+                                                 buffered=True)
+            self._paramstyle = mysql.connector.paramstyle
+        elif aur_db_backend == 'sqlite':
+            aur_db_name = aurweb.config.get('database', 'name')
+            self._conn = sqlite3.connect(aur_db_name)
+            self._paramstyle = sqlite3.paramstyle
+        else:
+            raise ValueError('unsupported database backend')
+
+    def execute(self, query, params=()):
+        if self._paramstyle in ('format', 'pyformat'):
+            query = query.replace('%', '%%').replace('?', '%s')
+        elif self._paramstyle == 'qmark':
+            pass
+        else:
+            raise ValueError('unsupported paramstyle')
+
+        cur = self._conn.cursor()
+        cur.execute(query, params)
+
+        return cur
+
+    def commit(self):
+        self._conn.commit()
+
+    def close(self):
+        self._conn.close()