Installation improvements

[Chocobo1]

It would be best if we provided lower resolutions icons, but my DE (cinnamon) can do the downsize (256 to lower res) perfectly.

[coveralls]

Coverage remained the same at 94.382% when pulling 1eb5911 on Chocobo1:install into 85611b8 on chewing:master.

[Chocobo1]

@jserv @czchen
IMO, the version string should bump after merging this, because chewing-editor.desktop were installed to the wrong dir before this fix.

[czchen]

@Chocobo1

I guess you mean changing version to 0.1.0 instead of 0.0.4 ? I think this can be considered as bugfix (fix typo in chewing-editor.desktop install path), as well as new feature (since chewing-editor.desktop never works before this commit, we can consider it as a new feature). So both 0.1.0 and 0.0.4 are fine with me for the next release.

[Chocobo1]

I guess you mean changing version to 0.1.0 instead of 0.0.4 ?

I was thinking 0.0.4, but 0.1.0 is fine for me too. Your decision :)

Speaking of this, I always think this program is somewhat stable & functional, personally I would give it a 1.0 version (in sense of a first stable release).

[czchen]

I think we can release 1.0.0 once the #2 and #108 are fixed.