new branch to fix documentation

[SVN r60575]
Spirit: fixed some typos in documentation

[SVN r60576]
merged changes from previous incarnation of this branch
svn merge -r56197:56494 https://svn.boost.org/svn/boost/sandbox-branches/birbacher/fix_documentation@56494 .


[SVN r60577]
Boost.Log merged to trunk.

[SVN r83860]