Guard against a possible NULL
Improvement to account alias expansion

Aliases are now expanded not only if they occur by themselves, but also
if they occur as the beginning of a multi-part account.  Given <alias
Food=Expenses:Food> the account <Food:Tomatos> should now be expanded to
<Expenses:Food:Tomatos>.
escape @ characters properly so they show up
Merge branch 'next' of github.com:ledger/ledger into next
convert doc/Makefile to CMake

CMake will build the pdf version of the manual if texi2pdf is installed.
It will be installed to DOCDIR/ledger{,3}.pdf, for example
/usr/local/share/ledger/ledger3.pdf.
Also, the man page will be installed to MANDIR/man1/ledger.1

The option BUILD_DOCS is now on by default.

A new option BUILD_WEB_DOCS is used to toggle the generation
of the html version of the manual and the man page (off by default).

All this is added to the 'doc' make target.
Merge pull request #119 from kljohann/cmake.docs

convert doc/Makefile to CMake
fix issue for separate build dir
Merge pull request #120 from kljohann/cmake.docs

fix issue for separate build dir
repair doxygen support
Merge pull request #121 from kljohann/cmake.doxy

repair doxygen support
Merge remote-tracking branch 'upstream/next' into next
fix for 'store absolute paths internally'

`parent_path` was called on unprocessed path
so neither `resolve_path` nor `filesystem::absolute` had any effect.
remove superfluous 'break'
add unit tests for amount_t→floor/ceil
fix bug 788: behaviour of source_context for '-f -'

`session_t::read_data` did not set context.pathname to `/dev/stdin`
for the special case `-f -`. I chose to adjust `source_context` too
as there is no sensible context if no file name is provided.
fix bug 748: option aliases not recognized
Fixed ledger-add-entry

copied ledger-iterate-entries, ledger-set-year and ledger-set-month
from the old ledger.el.  Changed ledger-add-entry to use
ledger-exec-ledger vice the old ledger-run-ledger.
Merge pull request #122 from enderw88/Lisp-fixes

Fix ledger-add-entry
whitespace cleanup
On the Mac, texi2pdf doesn't have a --tidy option