Update src/core/session.cpp

Backend is not set properly with connection pool
fixed sqlite3 test
Merge remote-tracking branch 'snikulov/fix_for_15' into issue-15
Merge remote-tracking branch 'upstream/master' into issue-15
Update to Sergei Nikulov's fix for issue #15

Clarify supported sequence of statement::execute(false|true) and
statement::get_affected_rows() calls across all backends:
1. execute(false) and empty destination does not execute statement, but
prepares for subsequent statement::fetch() requests.
2. execute(true)  and empty destination calls requests backend to
execute statement.
3. execute(false|true) causes bulk fetch to destination, with
withDataExchange=false|true ignored.
Moved relevant test to common tests, confirmed it passes for all but
Oracle (get_affected_rows not implemented) and Firebird (I have no means
to test).
Related discussion at
http://sourceforge.net/mailarchive/message.php?msg_id=30312517
Thanks to Sergei who first proposed this behaviour as reliable and
consistent option, yet not intrusive.
Update to Sergei Nikulov's fix for issue #15

Clarify supported sequence of statement::execute(false|true) and
statement::get_affected_rows() calls across all backends:
1. execute(false) and empty destination does not execute statement, but
prepares for subsequent statement::fetch() requests.
2. execute(true)  and empty destination calls requests backend to
execute statement.
3. execute(false|true) causes bulk fetch to destination, with
withDataExchange=false|true ignored.
Moved relevant test to common tests, confirmed it passes for all but
Oracle (get_affected_rows not implemented) and Firebird (I have no means
to test).
Related discussion at
http://sourceforge.net/mailarchive/message.php?msg_id=30312517
Thanks to Sergei who first proposed this behaviour as reliable and
consistent option, yet not intrusive.
playing with binding output parameter as string instead of double
Fix .travis.yml syntax
Tweak .travis.yml output
Print Firebird tests heading
Remove superfluous call to test_bytea()
Fix memory leak of statement backend (issue #67)

The leak has been confirmed usign memory debugger. Applied fix suggested
by Evgeny Barabanov to perform allocated statement clean up if exception
is thrown from prepare() method.
Relax test_issue76 assertion (issue #67)

It seems ODBC on Linux is not causing exception as expected - to be
checked
Merge pull request #68 from mloskot/issue-67

Fix memory leak of statement backend (issue #67)
Merge pull request #5 from ghost/patch-1

Backend is not set properly with connection pool
Improve fixes in pull #5

* Ensure connection is established and backend set for session (thanks
to @kzeslaf for reporting this)
* Add test_pull5 to ensure no crash occurs (see Krzysztof's example in
pull #5 comments)
* Add test0 testing connection ensured
* Add test31 with basic use of connection_pool (no multiple threads,
sequential use only)
Merge pull request #69 from mloskot/pull-5

Improve fixes in pull #5
Firebird: Temporarily solve the problem with passing decimals to and fro without conversion
Merge pull request #71 from vnaydionov/master

Firebird backend specific: add option to fetch decimals as strings
Fix connection parsing in SOCI Firebird backend to handle spaces in values.

Really parse the connection strings instead of just breaking them on spaces.
This allows to detect errors such as not using "key=value" syntax at all but
most importantly allows to use spaces inside the values, as can be necessary
for the "service" parameter value when using embedded Firebird as the file
names can contain spaces.

Signed-off-by: Vadim Zeitlin <vz-soci@zeitlins.org>