Unordered: Merge from trunk

- Avoid an incorrect MSVC unused variable warning in the tests.
- Remove a `try..catch`.
- Adjust SFINAE use to try to supprt g++ 3.4. Fixes #7175.
- Fix some use of rvalues.
- Extra info in `at_tests`.



git-svn-id: http://svn.boost.org/svn/boost/branches/release@79868 b8fc166d-592f-0410-95f2-cb63ce0dd405
Merge some link fixes.

git-svn-id: http://svn.boost.org/svn/boost/branches/release@79869 b8fc166d-592f-0410-95f2-cb63ce0dd405
Merge bugfix for volatile types (refs #7157)

git-svn-id: http://svn.boost.org/svn/boost/branches/release@79871 b8fc166d-592f-0410-95f2-cb63ce0dd405
xpressive bug fixes merged from trunk: [79726], [79732], [79761], [79763], [79765], [79766], [79789]

git-svn-id: http://svn.boost.org/svn/boost/branches/release@79885 b8fc166d-592f-0410-95f2-cb63ce0dd405
Merged typos in comments to release; no functionality; Fixes #7210

git-svn-id: http://svn.boost.org/svn/boost/branches/release@79929 b8fc166d-592f-0410-95f2-cb63ce0dd405
merge [79918] from trunk, fixes #7203

git-svn-id: http://svn.boost.org/svn/boost/branches/release@79934 b8fc166d-592f-0410-95f2-cb63ce0dd405
update from trunk fixing http://boost.2283326.n4.nabble.com/fusion-g-4-6-deque-and-c-0x-compile-error-td4632499.html

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context: remove PDFs from documentation section


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context: remove links in documentation


git-svn-id: http://svn.boost.org/svn/boost/branches/release@79963 b8fc166d-592f-0410-95f2-cb63ce0dd405
Merging to release; Fixes #6576

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merge to release

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merge to release

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Revision history.

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Merge from trunk.

git-svn-id: http://svn.boost.org/svn/boost/branches/release@80003 b8fc166d-592f-0410-95f2-cb63ce0dd405
Deleting all generated html docs before submitting new ones. For 1.51.0. Permission by Eric Niebler.

git-svn-id: http://svn.boost.org/svn/boost/branches/release@80036 b8fc166d-592f-0410-95f2-cb63ce0dd405
Merged revision(s) 80027 from trunk/libs/icl/doc/html/boost/icl:
Cleaned up generated html documentation after hint by Michel Morin.



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Thread: merge fix for #6174

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Thread: Merge fix for #7185

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heap: merge fix for #7233



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Hash: Merge C++11 forward declaration fix.

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