Add variable smart-selector.

With the variable `smart-selector' it is possible to control whether
smartscan will look for either
(thing-at-point 'word) or
(thing-at-point 'symbol)
Merge pull request #1 from ranulf/master

Add variable smart-selector.
rename identifiers to be prefixed by smartcan

renamed to create the pseudo-namespace as promoted by MELPA maintainers
fix comments by prefixing smartscan where appropriate
turn smartscan into global minor mode with keymap
add installation comments
add installation comments to README.md
Fix typo
Add contributions
Rename smart-selector to smartscan-symbol-selector
Rename minor mode smartscan to smartscan-mode to conform with Emacs convention.
Update docstring for smartscan-mode to explain what it does.
Update documentation
Rename package to "smartscan" for consistency's sake.
Fix invalid function error

Macros must be defined before the first use.

Otherwise the byte compiler fails to expand the macro during
compilation.  Depending on the Emacs version this either degrades
performance, because the macro is expanded and interpreted dynamically
on each invocation, or even results an invalid function call, because
the byte compiler compiles to a standard function call, though it should
have done macro expansion.
Provide a separate global mode

It should be possible to enable/disable smartscan-mode on a
per-buffer basis, so a global mode alone is not an ideal
solution.

This commit makes smartscan-mode a regular minor mode, and adds
a globalized version called global-smartscan-mode which will
enable it everywhere by default.

This commit also fixes a typo in the "Install" comments
(smartscan vs smartscan-mode), and re-formats the header so that
all information will be extracted from the Commentary by
package.el and made available by package repositories for when a
user presses "?" in the `list-packages` buffer.
Merge pull request #7 from lunaryorn/fix-invalid-function-error

Fix invalid function error
Merge PR #8
Clarify commentary a bit
Update contributions.
Add Version and Maintainer to the header.
Indicate the file is not part of Emacs as per convention.