Moved V8 util function to V8Utils.
First draft for setting the music delivery callback and retrieving a buffer with the audio data.
Further work in progress on issue-52.
This commit provides (mainly):
* useNativeAudio and useNodejsAudio
* compile flag --native_sound=true|false
If adding tracks to a playlist fails an exceptions is now thrown. Fixes
SP_PLAYLIST_TYPE_PLACEHOLDER can be treated exactly like a SP_PLAYLIST_TYPE_END_FOLDER
Removed all std::couts from session callbacks.
If the login fails the ready callback will now be called with an
Javascript exception. Fixes #62.
Merge branch 'issue-62' into development
PLAYLIST_TYPE_PLACEHOLDER constant
local links
Added QtCreator files and node_modules to gitignore.
Merge pull request #63 from nzoschke/issue-37
SP_PLAYLIST_TYPE_PLACEHOLDER can be treated exactly like a SP_PLAYLIST_TYPE_END_FOLDER

# especiallg if itemerges an updated upstream into a topic branch.
#
# Lines starting with '#' will be ignored, and an empty message aborts
# the commit.
Merge pull request #64 from nzoschke/localtrack
local links
Moved ownership of Player and AudioHandler to the application / NodePlayer instead of singleton and Spotify.

Implemented NodeJS audio with a timer instead of asynchronuous callbacks.
Some cleanups
Merge branch 'issue-52' into development

Conflicts:
	src/callbacks/SessionCallbacks.cc
Renamed native_sound to native_audio for consistency. Default value is now true so the basic npm install is as before.
V8Browseables can now make their handle persistent.

Used in Search, Artist and Album to make the handle persistent before
executing the search/browse and then releasing the persistent handle
after the callback has been called.

Fixes #75.
Current second is now reset on stop.

Made it compatible with the new AudioHandlers, too.

Fixes #74.
For #55: Search now has indexed accessors. Added deprecated property accessors as well.
playTokenLost callback provided on the spotify object.

Fixes #60.