Make el-get-start-process-list fail when program is nil

This fixes #1545.
Use el-get-executable find in el-get-http-tar-install

This makes the http-tar method fail if no "tar" executable
can be found, see #1545.
add recipe for bbdb-
Flycheck comes with a prebuilt info file now
Popwin has additional features in 'misc'
add function-args recipe

function-args package provides better completion for C++, shows
documentation for C++ function arguments, etc.
Merge pull request #1546 from avdv/issue-1545

Implemented the proposed changes in #1545
Merge pull request #1547 from aki2o/bbdb-

add recipe for bbdb-
Merge pull request #1549 from dholm/bugfix/flycheck

Flycheck comes with a prebuilt info file now
Merge pull request #1550 from dholm/bugfix/popwin

Popwin has additional features in 'misc'
adding sublime-themes
Merge pull request #1551 from nicolamontecchio/master

recipe for sublime-themes
Recipe for sage-mode
Merge pull request #1553 from dholm/recipes/sage-mode

Recipe for sage-mode