Move some functions out of url_helpers.c into utils.c

Move

    username_to_name() and
    send_template()

into utils.c

This is the first step in removing url_helpers.[ch]

Signed-off-by: Andrew Clayton <andrew@opentechlabs.co.uk>
Move match_uri() from url_helpers.c into url_handlers.c

We can also mark this function as static as it is only used in
url_handlers.c

Signed-off-by: Andrew Clayton <andrew@opentechlabs.co.uk>
Move some functions out of url_helpers.c into audit.c

Move

    check_auth()
    is_logged_in()
    display_last_login()
    create_session()
    set_user_session()

into audit.c

We can also now mark get_last_login() as static as it is only used in
audit.c

Signed-off-by: Andrew Clayton <andrew@opentechlabs.co.uk>
Move remaining functions from url_helpers.c into csrf.c

Move the CSRF mitigation functions into a new csrf.c file.

Signed-off-by: Andrew Clayton <andrew@opentechlabs.co.uk>
No longer include url_helpers.h

Remove the url_helpers.h include from db.c and url_handlers.c as it no
longer contains anything.

Signed-off-by: Andrew Clayton <andrew@opentechlabs.co.uk>
Remove the remnants of url_helpers

Signed-off-by: Andrew Clayton <andrew@opentechlabs.co.uk>
Makefile: Prettify output and clean up

The main thing is to prettify the output, Whereas before you would get
output like:

    gcc -Wall -std=c99 -O2 -g -Wp,-D_FORTIFY_SOURCE=2 -D_FILE_OFFSET_BITS=64
    -fexceptions -fstack-protector --param=ssp-buffer-size=4 -fPIE -c
    utils.c -I../../libctemplate `pkg-config --cflags glib-2.0` `pkg-config
    --cflags gmime-2.0` `mysql_config --cflags`

for each C file. We now take a leaf from the Kernel and produce output
like:

      CC        utils.o

This grealty reduces the clutter and makes compiler warnings easier to
see.

Also set an objects variable that contains all the .o files to negate
the need to list them all out several times.

And remove the url_handlers.h file from the url_handlers.o target as
that header is not included there.

Signed-off-by: Andrew Clayton <andrew@opentechlabs.co.uk>