Fix Issue #8298, Don't throw exceptions on broken symlinks.

Using dirEntries to loop trough all the files/directories in a directory
will curently throw an Exception when encountering an broken symlink.

Whit this change DirEntry will no longer throw an Exception for broken
symlinks, but in that case isDir and isFile will return flase while
isSymlink returns true.
Merge pull request #1744 from 9rnsr/fix11603

Issue 11603 - std.algorithm.canFind does not work when needle is 1-byte zero
Merge pull request #1751 from dawgfoto/std_zip

[install,regression] fix Issue 11692 - can't set file attributes for std.zip.ArchiveMember
Revert "Merge pull request #1751 from dawgfoto/std_zip"

This reverts commit 67933fda951ccd8735eb66ea223980ae7175bc11.
Merge pull request #1772 from MartinNowak/fix10710

fix Issue 10710 - phobos depends on versioned libcurl

Conflicts:
	posix.mak
Revert "Merge pull request #1744 from 9rnsr/fix11603"

This reverts commit 13b8101061b2e5824c0e0a08654922649acf4978.
fix Issue 11831 - std.zip no longer allows setting madeVersion field

- add deprecated ref accessor
[trivial] remvoe trailing whitespace
fix issue 11808
adjust documentation to reflect new capabilities
fix issue 11839
add _ to allowed characters in regex identifier
fix issue 11350

Do not throw on bad UTF inside of a C callback
fix issue 8203, similar issue with lookaround

When using a temporary engine as closure its generation counter
should be tracked separately for each lookaround.

For now just use built-in AA, later we could find better places
to store this counter in.
Merge pull request #1841 from blackwhale/issue-8203

fix issue 8203, similar issue with lookaround
Merge pull request #1838 from blackwhale/issue-11839

Fix issue 11839
Merge pull request #1837 from blackwhale/issue-11808

Fix issue 11808 std.uni.CodepointSet('А', 'Я'+1, 'а', 'я'+1) asserts
Merge pull request #1142 from MikeWey/Issue8298

Fix Issue #8298, Don't throw exceptions on broken symlinks.
Merge pull request #1842 from blackwhale/issue-11350

Fix issue 11350 ibphobos2 regex match segfaults when a rare HTTP header is received
Remove trailing white