Add a few more countries to Asia and Southeast Asia.

[mwichary]

(Note: You might want to do #228 at the same time.)

Bahrain and Maldives are missing from the first, and Singapore from both.

Those were not present in the files from Natural Earth, and Natural Earth site today is only half-accessible. It should be otherwise possible to merge in the missing countries from http://www.naturalearthdata.com/downloads/10m-cultural-vectors/10m-admin-0-details/ or elsewhere on the site.

References:
http://en.wikipedia.org/wiki/List_of_sovereign_states_and_dependent_territories_in_Asia
http://en.wikipedia.org/wiki/Southeast_Asia