Sun zenith angle correction added.
Initial commit of mpop.tools (with Sun zenith angle correction).
Revert to original version
Sun zenith angle correction split into two functions.
Test cases for channel.sunzen_corr().
Clarification to help sunzen_corr_cos() desctiption.
Channel desctiptions are added.
Channel descriptions added.
Typo.
Extra tests for sun_zen_corr().
A section on mpop.tools added to documentation.
Merge pull request #8 from pnuu/pre-master

Sun zenith angle correction added.