usermanual: Renamed manual dir to user-manual to be consistent.

Renaming the manual directory to user-manual in order to allow
for future additions of specific manual types, such as a
dev-manual.

Signed-off-by: Bill Traynor <wmat@alphatroop.com>

diff --git a/doc/manual/Makefile b/doc/user-manual/Makefile
similarity index 100%
rename from doc/manual/Makefile
rename to doc/user-manual/Makefile

diff --git a/doc/manual/html.css b/doc/user-manual/html.css
similarity index 100%
rename from doc/manual/html.css
rename to doc/user-manual/html.css

diff --git a/doc/manual/usermanual.xml b/doc/user-manual/usermanual.xml
similarity index 100%
rename from doc/manual/usermanual.xml
rename to doc/user-manual/usermanual.xml