os-agnosticsm and install script

[1vn]

need to make this easy for non technical users to install, should target popular OSes

[keeferrourke]

Also related: .imgrep directory for storing sqlite db is not Windows friendly.

[1vn]

ignore MACOS files like .DS_STORE and thumbnails

[keeferrourke]

PR #9 is about as much as I'm willing to do for windows compat

[keeferrourke]

will look into using gnu autotools to generate that magic

./configure
make
make install

incantation that pretty much most software seems to use. should be distro-agnostic as well.

will probably be removing windows compat in future because its a pain.