In disk_build:

* Write deps file in indented rather than minified JSON

In jst_server:
* Change to ES6 modules
* Change to fsPromises
* Change to ES6 classes
* Remove unneeded dependencies
* Use Problem object internally instead of Server.die() and Site.die()
* For API endpoints, serve the JSON-encoded Problem object directly

In ndcode_site:
* Rework /my_account/sign_up/index.html.jst to use custom validation style, reduce to 2 steps (former steps 1 and 2 are now done together and resulting message is displayed in red underneath the step 1 buttons), and improve placeholder text
* Implement draft updating thread in /my_account/sign_up/index.html.jst (avoids possibility of concurrent draft updates), use oninput rather than onchange event
* Add random placeholder data generator (persists in session for 24 hours)
* Disable the "Create account" button and null draft when sign up form is blank
* In /my_account/sign_up/index.html.jst use HTML5 hidden attribute, not jquery
* In /my_account/sign_up/index.html.jst improve tick, cross, spinner, message
* Make tick, cross and spinner have no height, so they don't affect card header
* More comprehensive system for displaying icons vertically centred within text
* In /my_account/sign_up/index.html.jst add icons to every button
* Fix unnecessary extra syntax in /_config/Problem.mjs
* In /my_account/sign_up/index.html.jst use variables id_XXX instead of document.getElementById(), and add a script /ids.sh to easily create definitions for them
* In /my_account/sign_up/index.html.jst change placeholder for captcha text to xxxxxx (because the randomized value was too confusing), fix some minor bugs
* In /my_account/sign_up/index.html.jst improve layout around verification code
* Consistency changes for the Problem object
* Use jst_server.Problem everywhere, make /_lib/post_request.jst use jst_server's new error handling to serve the JSON-encoded Problem instead of doing it itself
* Change all the get_draft.json endpoints to be like sign_up one (simpler because the JSON from the database is returned directly, including the expires field)
* Update /my_account/verify_email/index.html.jst to latest way, no accordion
* Update /my_account/password_reset/index.html.jst to latest way, no accordion
* Update /my_account/verify_password/index.html.jst to latest way, no accordion
* Update /my_account/send_verification_email/index.html.jst to latest way, no accordion and now an inline form (need to improve label spacing when collapsed)
* Update /contact/index.html.jst to latest way, no accordion, placeholder company
* In /_lib/navbar.jst prefix all ids with navbar- for uniqueness
* In /_lib/navbar.jst use variables id_XXX instead of document.getElementById()
* In /lib/navbar.jst use HTML5 hidden attribute and remove some other jQuery
* In /lib/navbar.jst rework feedback to be similar to /contact/index.html.jst way
* In /lib/navbar.jst rework sign in to be similar to feedback
* Remove modal fade because of an annoying glitch during fade in/out (it seems to move slightly in the horizontal, which may be because of scrollbar visibility)

In sass_css_cache:
* Send style option to SASS to produce minified CSS output

diff --git a/disk_build b/disk_build
index 93cf74b..754f0c5 160000 (submodule)
--- a/disk_build
+++ b/disk_build
@@ -1 +1 @@
-Subproject commit 93cf74bc9455015d72091bad3fc19a160dcdc392
+Subproject commit 754f0c5629c1f3f5a874e8d712663306be3c77cf

diff --git a/jst_server b/jst_server
index 6d11514..386b5f7 160000 (submodule)
--- a/jst_server
+++ b/jst_server
@@ -1 +1 @@
-Subproject commit 6d11514b7d8009b4b5a083cb60858fdf88e27f2a
+Subproject commit 386b5f73d3c955ea21e177f738357078c295ff21

diff --git a/ndcode_site b/ndcode_site
index 398ac62..47ad54b 160000 (submodule)
--- a/ndcode_site
+++ b/ndcode_site
@@ -1 +1 @@
-Subproject commit 398ac6299aa57c59c04f16d29e6da54bf47f62d8
+Subproject commit 47ad54b04fe62459a0c6789aaa4f328ef0f421d7

diff --git a/sass_css_cache b/sass_css_cache
index 06e96b1..54e37ba 160000 (submodule)
--- a/sass_css_cache
+++ b/sass_css_cache
@@ -1 +1 @@
-Subproject commit 06e96b1b0b15e672a59aad8ab0c077d9b6348f47
+Subproject commit 54e37bad11c2e14a20498a6d5d3a776cdd1aa829