ui: Fix GUI initialization order #3488

I thought through the initialization order a bit. Fixes at least #3478. @diapolo can you please help testing?

Splits and documents the phases:

1. Parse command-line options. These take precedence over anything else.
2. Basic Qt initialization (not dependent on parameters or configuration)
3. Application identification
4. Initialization of translations
5. Now that settings and translations are available, ask user for data directory
6. Determine availability of data directory and parse bitcoin.conf
7. URI IPC sending
8. Main GUI initialization

Splits command line parsing logic from ipcSendCommandLine into ipcParseCommandLine, as isTestNet() can only be overridden in the early stages before choosing a data directory. Sending however needs to happen after choosing a data directory.

Tested:

• URI handling to running testnet and mainnet instances
• URI handling with custom data directories
• URI handling for testnet URIs launches testnet GUI
• -choosedatadir can be used to provide custom data directories

Automatic sanity-testing: PASSED, see http://jenkins.bluematt.me/pull-tester/2102ab9f5cb542e6727e0f25e670d8549aa1bf1a for binaries and test log. This test script verifies pulls every time they are updated. It, however, dies sometimes and fails to test properly. If you are waiting on a test, please check timestamps to verify that the test.log is moving at http://jenkins.bluematt.me/pull-tester/current/ Contact BlueMatt on freenode if something looks broken.

I'll see if I can check this out today or tomorrow...

I can confirm this is working: -choosedatadir can be used to provide custom data directories

Great!

Agree with the code changes too? I didn't make any obvious logic errors?

I'd like to also take a look at URI handling before giving a final ACK. Currently I need to resync my mainnet testnode. Changed init orderd looks fine to me...

I can confirm URI and payment-request handling with a running instance is working. I can't test click-to-start-Bitcoin, as I depend on command-line switches ;).

ACK