Installer: shared memory configuration for PostgreSQL

Fixes #450 - PostgreSQL fails to start.

config/60-postgresql-shm.conf

@@ -0,0 +1,2 @@
+kernel.shmmax=2147483648
+kernel.shmall=2097152

config/client_sftp_batch

@@ -8,3 +8,4 @@ put config/create-postgres.sql
 put config/postgresql.conf
 put config/pg_hba.conf
 put config/usr.sbin.mysqld
+put config/60-postgresql-shm.conf

installer.py

@@ -418,6 +418,7 @@ class Installer:
     sudo -u postgres -H /etc/init.d/postgresql stop
     sudo mv postgresql.conf /etc/postgresql/9.1/main/postgresql.conf
     sudo mv pg_hba.conf /etc/postgresql/9.1/main/pg_hba.conf
+    sudo mv 60-postgresql-shm.conf /etc/sysctl.d/60-postgresql-shm.conf
 
     sudo cp -R -p /var/lib/postgresql/9.1/main /ssd/postgresql
     sudo -u postgres -H /etc/init.d/postgresql start