Rename configure.in as suggested by autoconf.

The configure.in name is deprecated.  Autoconf suggests naming its
input file configure.ac, so let's stick with the standard.
Add some missing checks spotted by autoscan.

Also explicitly specify the AC_CONFIG_AUX_DIR.
Switch to autoreconf invocation.

Replace autoconf with autoreconf in Travis script and README, as
recommended for the autotools suite.  This will also regenerate
config.h.in using autoheader, so remove it from the repository.
Let autoconf handle the compiler C99 mode.

Use the autoconf-provided @CC@ substitution as well as @CFLAGS@ and
@LDFLAGS@ in Makefile.in.
Remove explicit -O3 flag.

This should be set using configure, so remove the explicit default
value.
Port the tests/ directory to use autoconf.

Use autoconf's @CC@ and @CFLAGS@ configuration in Makefile.in.
Ignore file config.h.in generated by autoheader.
Move AC_CONFIG_HEADERS toward the end.

Output of config.h should be listed along with the other output files.
Add configuration to use automake and libtool.

Replace Makefile.in with Makefile.am in top level and src directory.
Add missing macro calls in configure.ac and move AC_PROG_CC_C99 before
LT_INIT.  Include src/Makefile in AC_CONFIG_FILES.

Tests are not yet implemented in the new automake-based build system.
Remove install-sh copied from automake.

Automake will re-add this file when run with the --install option, so
there is no need to keep it in the repository.  Update Travis
configuration and README.md to include the --install option for all
missing files.
Add automake configuration for include/ directory.

Let automake know about the cintelhex.h header file to be installed.
Migrate tests/ directory to automake.

Add Makefile.am to build test binary and use it for the check target.

The #include'd source files test_*.c must be in EXTRA_DIST because
they cannot be compiled using test_SOURCES, but must be distributed
with the package.  This should be fixed sometime to build separate
object files for each and link them together for the test binary.
Clean up .gitignore files.

Reorder entries, add new files generated by automake / libtool and
split up for each subdirectory.
Clarify README.md regarding autoreconf.

Not only the configure script needs to be regenerated in a Git
checkout, but the whole build system now that we use automake /
libtool.
Merge pull request #22 from acolomb/cleanup-autoconf

Clean up autoconf build system
Merge pull request #18 from acolomb/get-address-range

Add new API function ihex_get_address_range()
Avoid target-specific compiler flags in tests/Makefile.am.

Some versions of GNU Automake seem to require an extra autoconf check
when some Makefiles contain target-specific compilation flags (in this
case, -I flag for the tests).  To avoid this extra check, we can just
set the include path flag globally in AM_CPPFLAGS.
Adjust Travis configuration for renamed check target.

The GNU standard target name to run the test suite is "check",
implemented by automake.  Let's stick to this convention...
Reorder program checks in configure.ac.

Add an explicit check for AC_PROG_CC before checking for C99 mode and
move the macros under the correct heading.
Add myself to authors list.