Fixed include style in accordance with recent libmaple versions

Signed-off-by: Dmitry Prokhorov <dipspb@gmail.com>
Minor README fix, list renumbered

Signed-off-by: Dmitry Prokhorov <dipspb@gmail.com>
Minor README fix, tab name added

Signed-off-by: Dmitry Prokhorov <dipspb@gmail.com>
Minor typo fix in README

Signed-off-by: Dmitry Prokhorov <dipspb@gmail.com>
README.txt tweaks.

Try to clarify the language describing USER_MODULES and the rules.mk
files.

Signed-off-by: Marti Bolivar <mbolivar@leaflabs.com>