Make some patches multi-version

[pgaskin]

There are quite a few patches which take a bit of time to update (usually multiple int replacements), but don't change relative offsets often.

The CSS patches have already been simplified for v52.

The following patches will be made multi-version for 4.15.12920 or 4.17.13651+:

• [X] Sleep/power-off timeouts (138b6d6f1fbee64620ef90f03301575be4eb5cf3)\
  • Value offsets have been the same for a while.
  • If something changes, the patch will fail (offsets are spread around the function).
• [X] Custom kepub default margins (bdaa026e751a89f7ec3f9124c7eb4fa1684562ab)
  • Same as previous.
• [X] Change dicthtml strings to micthtml (a33da350b7d47742fab41ccb3b7262bcf69895aa)
  • Strings have been the same for a while.
  • A null byte was added to prevent matching the wrong string.
• More?

Patches will be made multi-version if they:

• Are relatively simple.
• Will fail to build if something changes rather than causing side effects or segfaults (e.g. nothing with ReplaceBLX).
• Are simple enough to figure out from the multi-version one (i.e. if someone else needs to figure out how they work, it should be relatively obvious and not require comparing files before and after the patch).
• Will work in at least 2 versions.
• Are able to have unique ways to identify replacements (e.g. not replacing a specific instance of a string appearing multiple times).
• Do not require additional attention on upgrades (e.g. not depending on constants which are likely to change, such as the smartlink patches).
• Have relative offsets less than 1000.

And a quick note: Due to some implementation details in the kobopatch symbol-finding, offsets from a symbol found by other tools will usually need to be decreased by 1 to work.

[pgaskin]

This is all I will do for now, but I'm taking another look at resolving ARM PLT offsets, which would allow me to make ~80% of the rest of the single-version patches multi-version.