Update all translations from Transifex.

The translation memory was able to automatically translate some translations.
Fix some possible loss of data warnings on x64.
PlayerNavigationDialog: Remove unreachable code.

Remove the assert since it can fail in normal situations.
PlayerNavigationDialog: Initialize m_bChannelInfoAvailable.
WebServer.cpp: Add some error checking for debug builds.
Cosmetic: Tweak the OSD message for audio delay changes.

Make it consistent with the OSD message for subtitle delay changes.

Fixes #4989.
Grammatical fix: Units should be preceded by a space in English.

Translations completely identical to the English version have been reset to encourage the translators to double-check that the translation was really correct.
Fix: The "Channels" sub-menu was not translated.

I forgot to use the string I added in c311c1f9e3dad6ef74c666ee22b45b1f6e01b7da.

Fixes #4994.
DVB: Add a special case for SetChannel at first start or after clearing all channels.

We don't want to assert in this case since it's expected that we have no channel to set.

Also make nDVBLastChannel a signed integer for consistency with the rest of our API.
DVB: Make sure the preferred channel number always stay consistent.

Moving a channel up/down or sorting by LCN wouldn't update the preferred channel numbers which caused strange behaviors when going to next/previous channel or when using "Navigate" menu.
DVB: The content of the "Information" panel was lost when changing the UI language.

Fixes 4993.
DVB: Correctly enable the "Information" panel when clicking the "Info" button.

Previously, enabling the "Information" panel using the "Info" button on the "Navigation" dialog would reduce the size of the main window when hiding the panel from the "View" menu.

Fixes #4992
Don't force any background color for the Shockwave graph.

This commit fixes #1747.
WebUI: Inform the web interface that no audio stream is available.