Improve Embedded Python Support

Discussion:
https://groups.google.com/d/msg/ledger-cli/kq9sKoRX9vw/fmyhvPslzokJ
Merge pull request #330 from eliptus/feature/embedded-python

Improve Embedded Python Support
Fix minor navigation bugs.  Prev and next act now properly handle directives and empty lines
Handle E and O for months and comma separate list of numbers for months and days.
Handle base-date + integer * day of week.  i.e. 2014/11/27+2Th for every other Thursday start 2014/11/27
Minor code cleanup
Handle count day of month, i.e.  third Thursday is */*/3Th,  every Thursday is */*/0Th
Fixes act having higher priority than region
Remove s-trim functions since they stomp on s.el.
Merge branch 'prefix-s-trim-functions' into schedule-compiler-improvements
Merge pull request #331 from rnkn/patch-1

Fixes xact having higher priority than region
Fix and re-enable DocTests
Change Travis CI build status icon fromat to SVG
Merge pull request #334 from afh/pull/svg_build_status

Change Travis CI build status icon fromat to SVG
Cleaned up commodities and completion code.
Merge pull request #333 from afh/pull/DocTests

Fix and re-enable DocTests
support date as well as datetime in Balance.value()

cargo-cut'n'paste from py_amount.cc
Merge pull request #336 from csrhodes/master

support date as well as datetime in Balance.value()
Simplifies parsing of the beginning of an act.  This allows fontifying effective dates.
Merge branch 'master' into ledger-mode-code-cleanup