SDK: move IntListPreference to SDK package

move IntListPreference to the SDK extension package.
TouchImageView: use MathUtils.clamp()
TouchImageView: implement 3-stage scaling
TouchImageView: remove old commented code
Model: add new function Post.getWebUrl()
[1/2] PostDetail: add "View in browser"
[2/2] PostList: add "View in browser"
PostList: setQuery() on search view expand

still do setQuery() during onMenuItemActionExpand(), because sometimes
the query is set outside SearchView actions (such as clicking on the tag
list).
TouchImageView: remove Log
Database: add default search_count

if we don't do this, the tags fails to insert.
ignore on conflict anyway, shouldn't overwrite existing search_count.
PostList: close cursor after Post constructed
SiteAPI: seek to proper position when building tags
Database: database version 6

1. tweak select statement for `post_tags` view
2. add index for `post_tags_link__hashcode`
[1/4] Picasso: extract executors
[2/4] Picasso: adjust thread priorities
[3/4] Picasso: add network change receiver
[4/4] Picasso: respect network change
Picasso: don't change priority

the "fade-in" effect malfunctions.
PostDetail: pause autoplay on user interaction
App: remember network state