yaws_api: Make end tags HTML5-compatible in ehtml_expand

Currently, HTML generated by Yaws ehtml does not validate correctly as
HTML5 (e.g. using http://validator.w3.org/). The reason is that in HTML5
"void elements" like <br> must not have a closing end tag:

Forbidden: <br></br>
Allowed: <br>
Allowed (and also valid XHTML): <br />

Also, since the self-closing tag syntax ("/>") is simply ignored in
HTML5, some elements must have an end tag:

Forbidden: <p />
Allowed: <p></p>

This patch fixes both issues and also adds tests.

References:
- http://stackoverflow.com/questions/10598501/closing-tags-in-html5
- http://stackoverflow.com/questions/1946426/html-5-is-it-br-br-or-br
- http://www.w3.org/TR/html-markup/syntax.html#void-element
Update and synchronize ehtml documentation
yaws_api: Fix ehtml {check, _, number()} attributes

Attribute {check, Key, 10} should expand the same way as {Key, 10}.
yaws_api: Allow binary attribute values in ehtml

Binary attribute values are already supported in exhtml.
yaws_api: Cosmetics (reduce redundancy)
Fix building without PAM

Fixes this error in `make`:

    /usr/bin/install: cannot stat ‘epam’: No such file or directory
    make[1]: *** [post-build] Error 1
Fix typo in configure help (`--disable-pam`)
Merge pull request #184 from weisslj/fix-build-without-pam

Fix building without PAM (and small typo in configure help)
Merge pull request #183 from weisslj/ehtml-attribute-fixes

EHTML: Fix small bug, allow binary attribute values and update documentation
Document access logs as NCSA combined/XLF/ELF log format
Add test/eunit/subconfig_DATA to .gitignore
Exclude hipe application in reltool.config

Several users have reported problems building releases using
rel/reltool.config due to problems with hipe, so extend reltool.config to
exclude hipe.
Fix yaws_sendfile to correctly handle non-latin1 filenames

Fix a problem where a filename containing Chinese characters would cause
yaws_sendfile to die in a list_to_binary call.
Reloading the log could lead to an fd leak in the
case where we were having two servers on the same port,
i.e both http and https
Merge branch 'klacke-yaws-log-fd-leak'

Fd leak
Add 'honor_cipher_order' option in ssl part

This option can be used to set to true/false the 'honor_cipher_order' parameter
on the ssl socket. This option was introduced in SSL application in Erlang/OTP
17.0, so it will be ignored by Yaws for previous releases. When supported, this
option is set by default to true.
Fix features detection when rebar is used
Support subconfig/subconfigdir directives in the server part
Add --configtest option in Yaws script to check a configuration file
Fix yaws_debug module to get debug dump on recent Erlang/OTP releases