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