--enable-xxx/disable-xxx options in configure

[Maxim Reznik]

To write ebuild (instalation script for Gentoo) we need to add --enable-xxx/disable-xxx options in configure.

Here quote from Gentoo developer manual:

Often the configure script will try to automatically enable support for optional components based upon installed packages. This must not be allowed to happen. For example, if a user has Perl installed but has USE="-perl", packages with optional Perl support must not link against Perl. This automatic detection can usually be overridden using --enable- and --disable or --with- and --without- switches

​http://devmanual.gentoo.org/ebuild-writing/functions/src_configure/configuring/index.html

[vadim.godunko]

In [2357]:

Add specification for component's switches parser.

Refs #152.

[vadim.godunko]

In [2358]:

Add subprograms to check whether switches is specified in the command
line.

Refs #152.

[vadim.godunko]

In [2359]:

Add support for enable/disable of optional modules from command line.

Refs #152.

[vadim.godunko]

General support for --enable-<component>/--disable-<component> switches is added, and is used in Oracle, PostgreSQL and SQLite3 modules.