rename payee_mappings to payee_alias_mappings

(and similar renames) in preparation for payee_uuid_mappings
support payee uuid directive

The semantics of this are a little bit tricky: we want, if we come
across a transaction with exactly the given UUID, to set the
transaction's payee to be the specified one.

We need to set that payee before the first post in the transaction is
parsed, otherwise that post will inherit the wrong payee; however, we
need to do it after the transaction's tags have been parsed.  The
implementation as it is in this commit is potentially a little
wasteful, if there are post-like (non-comment non-assertion) entries
in the transaction that don't successfully parse as posts.
document payee uuid subdirective
Merge pull request #289 from csrhodes/payee-uuid-mapping

Payee uuid mapping
Add test case or new payee uuid feature
Remove trailing whitespace from error messages

Fix for bug #867
Ensure that directives have arguments if they need one

Ensure that account, commodity and payee directives have arguments
if they need one.  Bug fix for #785
Ensure that high-levels directives have arguments if they need one

Ensure that high-levels directives, such as account, alias and
commodity, have arguments if they need one.  Bug fix for #1036
Fix python example so it runs
Merge pull request #290 from tubaman/fix_python_example

Fix python example so it runs
Add a reference to Debian 8 in the build instructions

I successfully built ledger from git on Debian testing (jessie) as
of today (which will become Debian 8) with the packages listed in
README.md.
Typo fix
Lower down (from 1.55) requirements towards libboost
Fix some typos
Merge pull request #291 from thdox/ubuntu-14.04

Lower down (from 1.55) requirements towards libboost
Indent & untabify

M-x mark-whole-buffer
M-x indent-region
M-x mark-whole-buffer
M-x untabify
Merge pull request #292 from thdox/fix-lisp-indentation

Thank Thierry,
   I don't know when these got messed up but I have been meaning to do just this for some time.
Ease copy-paste by adding a continuation character
Some cleanup about doc/*
Remove redundant
Ignore shared libraries