Changing 'profile icon' to 'profile picture'

[Mitsuhiro Yoshida]

Branches: master

I think it's better to change en.utf8 lang strings as below:

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Lang file: blocktype.profileinfo.php
string: dontshowprofileicon

[before]
Don't show a profile icon

[after]
Don't show a profile picture

-----

Lang file: blocktype.profileinfo.php
string: uploadaprofileicon

[before]
You have no profile icons. <a href="%sartefact/file/profileicons.php" target="_blank">Upload one</a>

[after]
You have no profile picture. <a href="%sartefact/file/profileicons.php" target="_blank">Upload one</a>

-----

Lang file: admin.php
string: remoteavatarsdescription

[before]
If checked, the <a href="http://www.gravatar.com">Gravatar</a> service will be used for users' default profile icons.

[after]
If checked, the <a href="http://www.gravatar.com">Gravatar</a> service will be used for users' default profile picture.

-----

Lang file: mahara.php
string: registerstep3fieldsoptional

[before]
<h3>Choose an Optional Profile Image</h3><p>You have now successfully registered with %s! You may now choose an optional profile icon to be displayed as your avatar.</p>

[after]
<h3>Choose an Optional Profile Image</h3><p>You have now successfully registered with %s! You may now choose an optional profile picture to be displayed as your avatar.</p>

-----

Lang file: view.php
string: profileicon

[before]
Profile Icon

[after]
Profile Picture