Merge branch 'release/3.2.0' into develop
Fix linking
Some trivial optimizations in ODBC statement preparation code.

Don't use std::ostringstream unnecessarily; reserve space for the query string.
Merge pull request #111 from vadz/odbc-strstream

Some trivial optimizations in ODBC statement preparation code.
Install instantclient_11_2-linux-x64-mloskot.tar.bz2

Testing Oracle InstantClient installation from custom package hosted privately.
Add missing mkdir -p option
Use tar and bunzip2 instead of zip
Set ORACLE_HOME and related library path
Testing Oracle setup on travis-ci.org
[travis] Install libaio for Oracle InstantClient
[travis] Create libclntsh.so symlink to libclntsh.so.11.1
Remove redundant libclntsh lookup.

Oracle Client Code Library is deployed as libclntsh.so.11.1 on Linux and UNIX and oci.dll on Windows.
There is no separate libclntsh and liboci on unix.
[travis] Create libocci.so symlink to libocci.so.11.1
Merge branch 'hotfix/3.2.1' into develop

Conflicts:
	src/cmake/modules/FindOracle.cmake
Fix typo

[ci skip]
Add SOCI 3.2.1 contributors

[ci skip]
Update SOCI 3.2.1 release date

[ci skip]
Fix harmless warning about signed/unsigned comparison.

MSVC (and probably other compilers too) gave a warning about comparing size_t
argument of postgresql_vector_into_type_backend::resize() with the expression
that became integer after the change of 29cb6c7e, so make this expression
unsigned again.
Implement session::get_next_sequence_value() for PostgreSQL backend.

Use the same actual implementation as for the ODBC backend when using
PostgreSQL driver, i.e. "select nextval(sequence-name)".
Don't allow exceptions escape from postgresql_statement_backend dtor.

This fixes abnormal program termination if an error happened while executing a
prepared statement: it was then destroyed during stack unwinding and if
deallocating it failed as well, resulting in a call to terminate().

In practice, deallocation seems to always fail with SQL state 25P02 ("current
transaction is aborted, commands ignored until end of transaction block") when
it is executed inside a transaction.