pre_form: Feature to configure form parameters when opening specific site.

It would be convinient for sites where you often visit, but it may introduce
some security issues. Be careful to use this feature, especially `submit'
params described below.

Default configuration file for pre_form is ~/.w3m/pre_form.

Syntax as follows:

url <url>|/<re-url>/
form [<name>] <action>
text <name> <value>
file <name> <value>
password <name> <value>
checkbox <name> <value> [<checked>]
radio <name> <value>
section <name> <value>
submit [<name> [<value>]]
image [<name> [<value>]]
textarea <name>
<value>
:
/textarea

If <action> is set, form which has matched <action> attributes
will be configured by this pre_form.

The line begining with text, file, passwd, select, textarea means that
it will set value to <value> in input, select or textarea element which
name attribute matches with <name>.

The line beginning with checkbox, radio means that it will check
input element which name and value attribute matches with <name> and <value>
respectively. If <checked> is 0, no, or off, disable check of the checkbox.

The line beginning with submit or image means that it will submit input
element which name attribute matches with <name> (and value attribute
matches with <value>), or submit last <input type=submit> element if no
<name> specified.

You quote \, ' (single-quote) or " (double quote) as you do in shell.