Autodetect baudrate only if either a .ino/.pde is present

Because of the way the autodetect code works, if no .ino/.pde file is
present, then the makefile hangs
Allow building with Arduino core, without a .ino/.pde file

Till not it is not possible to build with Arduino core, without using a
.ino or .pde file. This commit removes that restriction.

However, the user has to explicitly include Arduino header files.

Fix #105
Added detailed instructions for using alternative cores

Should close Issue #60
Merge pull request #116 from sej7278/master

Add detailed instructions for using alternative cores

Fix #60
Added help target showing a summary of all the available targetsx
Added detailed instructions for using alternative cores

Should close Issue #60
Merge branch 'help' of github.com:dapicester/Arduino-Makefile into dapicester-help
Whitespace and formatting fix

No code or functionality change
Remove redundant list of targets

After #118, we have a separate target (help) to list all available
targets. Having this list in a single place is better, since we don't
have to make changes in multiple places when things change.
Make all executables overridable

This is helpful for #119 which will add support for colorgcc
Change the next version to 1.0.0, instead of 0.13.0

Lot of changes went it for this release and the code is stable enough
for 1.0.0
Revert "Make all executables overridable"

If these executables are not overridden in the child makefile, then the
default values are not set properly in the master makefile.

This complicates the solution for #119 :(

This reverts commit 66eec82a3af8ee5aa16e28230346e4a1f166da2b.
Add a README file for /examples folder

Fix #74
Add note about using colorgcc with this makefile

Fix #119
Bump up version to v1.0.0 for release
Fix link to colorgcc in readme
Unconditionally add `-D` in avrdude options.

This is needed in Mega boards, because of a bug in Mega bootloader. See
https://github.com/sudar/Arduino-Makefile/issues/114#issuecomment-25011005
for detailed explanation.

Fix #114
Fix whitespace and line spacing

No change in functionality
Bump up version to v1.0.1 for release

This is just a minor bug fix release
Don't append port details to avrdude for usbasp

When usbasp is used as programmer, there is no need to specify the port
to avrdude.

Fix #123