mdbx: release v0.11.6

The stable release with the complete workaround for an incoherence flaw of Linux unified page/buffer cache.
Nonetheless the cause for this trouble may be an issue of Intel CPU cache/MESI.
See [issue#269](#269) for more information.

Acknowledgements:
-----------------

 - [David Bouyssié](https://github.com/david-bouyssie) for [Scala bindings](https://github.com/david-bouyssie/mdbx4s).
 - [Michelangelo Riccobene](https://github.com/mriccobene) for reporting and testing.

Fixes:
------

 - [Added complete workaround](#269) for an incoherence flaw of Linux unified page/buffer cache.
 - [Fixed](#272) cursor reusing for read-only transactions.
 - Fixed copy&paste typo inside `mdbx::cursor::find_multivalue()`.

Minors:
-------

 - Minor refine C++ API for convenience.
 - Minor internals refines.
 - Added `lib-static` and `lib-shared` targets for make.
 - Added minor workaround for AppleClang 13.3 bug.
 - Clarified error messages of a signature/version mismatch.

Signed-off-by: Леонид Юрьев (Leonid Yuriev) <leo@yuriev.ru>

appveyor.yml

@@ -1,4 +1,4 @@
-version: 0.11.5.{build}
+version: 0.11.6.{build}
 
 environment:
   matrix:

src/man1/mdbx_chk.1

@@ -1,6 +1,6 @@
 .\" Copyright 2015-2022 Leonid Yuriev <leo@yuriev.ru>.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.TH MDBX_CHK 1 "2022-02-23" "MDBX 0.11.5"
+.TH MDBX_CHK 1 "2022-03-24" "MDBX 0.11.6"
 .SH NAME
 mdbx_chk \- MDBX checking tool
 .SH SYNOPSIS

src/man1/mdbx_copy.1

@@ -2,7 +2,7 @@
 .\" Copyright 2012-2015 Howard Chu, Symas Corp. All Rights Reserved.
 .\" Copyright 2015,2016 Peter-Service R&D LLC <http://billing.ru/>.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.TH MDBX_COPY 1 "2022-02-23" "MDBX 0.11.5"
+.TH MDBX_COPY 1 "2022-03-24" "MDBX 0.11.6"
 .SH NAME
 mdbx_copy \- MDBX environment copy tool
 .SH SYNOPSIS

src/man1/mdbx_drop.1

@@ -1,7 +1,7 @@
 .\" Copyright 2021-2022 Leonid Yuriev <leo@yuriev.ru>.
 .\" Copyright 2014-2021 Howard Chu, Symas Corp. All Rights Reserved.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.TH MDBX_DROP 1 "2022-02-23" "MDBX 0.11.5"
+.TH MDBX_DROP 1 "2022-03-24" "MDBX 0.11.6"
 .SH NAME
 mdbx_drop \- MDBX database delete tool
 .SH SYNOPSIS

src/man1/mdbx_dump.1

@@ -2,7 +2,7 @@
 .\" Copyright 2014-2015 Howard Chu, Symas Corp. All Rights Reserved.
 .\" Copyright 2015,2016 Peter-Service R&D LLC <http://billing.ru/>.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.TH MDBX_DUMP 1 "2022-02-23" "MDBX 0.11.5"
+.TH MDBX_DUMP 1 "2022-03-24" "MDBX 0.11.6"
 .SH NAME
 mdbx_dump \- MDBX environment export tool
 .SH SYNOPSIS

src/man1/mdbx_load.1

@@ -2,7 +2,7 @@
 .\" Copyright 2014-2015 Howard Chu, Symas Corp. All Rights Reserved.
 .\" Copyright 2015,2016 Peter-Service R&D LLC <http://billing.ru/>.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.TH MDBX_LOAD 1 "2022-02-23" "MDBX 0.11.5"
+.TH MDBX_LOAD 1 "2022-03-24" "MDBX 0.11.6"
 .SH NAME
 mdbx_load \- MDBX environment import tool
 .SH SYNOPSIS

src/man1/mdbx_stat.1

@@ -2,7 +2,7 @@
 .\" Copyright 2012-2015 Howard Chu, Symas Corp. All Rights Reserved.
 .\" Copyright 2015,2016 Peter-Service R&D LLC <http://billing.ru/>.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.TH MDBX_STAT 1 "2022-02-23" "MDBX 0.11.5"
+.TH MDBX_STAT 1 "2022-03-24" "MDBX 0.11.6"
 .SH NAME
 mdbx_stat \- MDBX environment status tool
 .SH SYNOPSIS