add bootstrap script for autoconf files generation

GNU Autotools requires a certain amount of boilerplate
initialization in order to generate a configure script.
Software projects that use Autotools usually place this
initialization in a shell script, often called bootstrap.

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
configure.ac: fix automake warnings

The commit fixes this:

  /usr/share/automake-1.14/am/ltlibrary.am: warning: 'libedcl-1.0.la': linking libtool libraries using a non-POSIX
  /usr/share/automake-1.14/am/ltlibrary.am: archiver requires 'AM_PROG_AR' in 'configure.ac'
  src/Makefile.am:3:   while processing Libtool library 'libedcl-1.0.la'

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
.gitignore: add autotools generated files

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>