PQconectdb.

This list is now freed when the last connection has been closed.

Closes: #6366

Itagaki Takahiro, with slight modifications.

Use bool as type for booleans instead of int.
Do not implicitely cast size_t to int.
Make the compiler stop complaining about unused variables by adding an empty statement.

ecpglib. Instead of parsing the statement just as ask the database server. This
patch removes the whole client side track keeping of the current transaction
status.

ECPG connect routine only checked for NULL to find empty parameters, but user and password can also be "".

provided by Andrew.

Replace leftover instances of _() by ecpg_gettext(), the latter being the
correct way to refer to the library's message catalog, instead of the one of
the program using the library.

Drop NLS support for ecpg_log(), which is a debugging instrument similar to
elog() in the backend.

We cannot support NLS in the ecpg compatlib, because that requires
ecpg_gettext, which is in ecpglib, which is not a dependency of compatlib.  It
doesn't seem worthwhile to worry about this, since the only translatable
string is "out of memory", and gettext probably won't be able to do much
without memory either.

Adjust messages to project style.

fix segfault on non-glibc systems.

Author: Euler Taveira de Oliveira <euler@timbira.com>

- Correctly parse connect options.
- Changed regression tests accordingly.

Removed one include file from connect-test1.

Created export list for ecpglib.

descriptor handling

to get memory allocation thread-safe. He also did some cleaning up.

- Really prepare statements
- Added more regression tests
- Added auto-prepare mode
- Use '$n' for positional variables, '?' is still possible via ecpg option
- Cleaned up the sources a little bit

  win32 threads.
- Fixed regression tests to run threading tests.

- Made some chars const as proposed by Stefan Huehner <stefan@huehner.org>.
- Synced parser and keyword lists.
- Copied two token parsing from backend parser to ecpg parser.
- Also added a test case for this.

Added patch by Joachim to work around OpenBSD bug in regression suite.

Made this option mark the .c files, so the environment variable is no longer needed.
Created a special MinGW file with the special error message.
Do not print port into log file when running regression tests.

Streamlined connection name parsing.
Added Joachim's patch to shorten paths before diffing.

- Fixed a memory leak/segfault in unsuccessful connection.
- Some changes to test files.

Merged dyntest.pgc and dyntest2.pgc.
Hopefully fixed the last Coverity reports (finally)

Implemented EXEC SQL UNDEF.
Applied first version of the regression test patch by Joachim Wieland <joe@mcknight.de>.

Connection identifier has to be unique

Added missing error handling in a few functions in ecpglib

<joachim.wieland@credativ.de>