Thin out "Status" and "Diagnostics" white at it, although the
overall static page conception isn't consistent at all.  Not
liking this, but something has got to be done.  Won't be the
last commit I think.  :)

(legacy) replace time with microtime in make_config_revision_entry, not needed for the config revision anymore because that method uses it's own timestamp. Revision entries are also used on some other config items, like firewall rules.

(mvc) add default config revision if none is given, fix for https://github.com/opnsense/core/issues/386

o comment blocks filled arrays disappear
o empty array tags disappear
o empty value tags collapse

This only leaves comment blocks in empty tags, which create
whitespace noise, which fucks up the config.xml real bad,
rippling through to the code that deal with is_array, isset
and actual = array() assignments to fix the faulty config.
Will clean this up one by one later.

Submitted by: Calexium

Yay, thanks, Wallace!

128M has some crash reports attached, but "modern" i386 systems
have more RAM to spare, too.  Also remove two old expansions to
64M, which are now restrictions, because when they were introduced
the memory limit was 32M.  ;)