Testing 76f19aa3f06a6501ad42ffd90736ccbc02bc469f

Fix race between workers and changing directory

Directory changes now create an Event that synchronizes with Layout by
stopping all the thumbnail workers and creating a new AvatarPicker with
the updated path.

Testing 09d0d18defe80c8497df74a2cc0edd41cc70b8af

resize avatar picker images in worker threads

for each call to Layout, create a thumbnail cache and populate it from
the last thumbnail map for each of the keys (filenames) that belong in
the thumbnail cache by iterating over the filenames. If an operation is
already busy, wait for it to complete before scheduling more thumbnails
to the workers. When the cache grows too large, prune the entries and
let gc free memory of thumbnail images.

Testing 9b0ffba7fb3e38a4a105fe5840966554fb877a55

test_9b0ffba7fb3e38a4a105fe5840966554fb877a55

Clear cached avatar on DeleteContact

Testing 015660cd31923ca4cb4f9a2735c68bf5a9a5dd5c

fix image scaling

On platforms with different pixel density the avatar may not render the
same as when laid out on the contact list. This fixes this
inconsistency.

Testing 2f27aa3aa2175b3b90680ffaa2484141d49c7622

test_2f27aa3aa2175b3b90680ffaa2484141d49c7622

Make debug profiler optional

Testing a3cbbdb06163784dc41fe7875b609f6ee8961eda

test_a3cbbdb06163784dc41fe7875b609f6ee8961eda

cache dirlist in avatar picker

Testing 0636481191312ad5aaae3ebcb0be6ee215d9df8e

test_0636481191312ad5aaae3ebcb0be6ee215d9df8e

update pinned gio and foreground usage

Testing 0904d74cabdd24fc7223b49e2bf55ed6b1fef5d3

test_0904d74cabdd24fc7223b49e2bf55ed6b1fef5d3

update missing go.sum for pinned gogio

Testing ebcd29221c59ff3fd44f408d150a862c1a5c0628

test_ebcd29221c59ff3fd44f408d150a862c1a5c0628

debounce escape key; catch back keypress

Testing 99a2df7bc3cd22654fd22501422c48e30169280e

test_99a2df7bc3cd22654fd22501422c48e30169280e

install gogio with go install