[pvr] Fix missing recordings

This fixes an issue with missing recordings that occurs under following
circumstances:

- Recording A in subdirectory "TV Show XY"
- Recording B in subdirectory "TV show xy"

Because of the difference in case, recording B won't show up in any
sub folder. This can happen due to EPG inconsistencies.

The presented sub folders are created with case-insensitive matching
using CFileItemList::Contains in GetSubDirectories.
But when determining if a recording belongs into a directory, the
comparison is case-sensitive (in IsDirectoryMember).

This commit changes the IsDirecroryMember check to be case-insensitive.
StringUtils: add "isasciidigit", "isasciixdigit", "asciidigitvalue", "asciixdigitvalue", "isasciiuppercaseletter", "isasciilowercaseletter" and "isasciialphanum" for locale-independent ASCII operations
RegExp: add automatic UTF-8 mode based on given regular expression
Usage of RegExp: change from forced UTF-8 mode to new automatic UTF-8 mode
XBMCTinyXML: use new RegExp constructor
ScraperParser: add new attribute "utf8" for scraper RegExp, works similar attribute "cs", possible values "yes", "no", "auto" ("auto" by default)
LinuxRendererGL: make sure we have a shader defined
HttpHeader: fix: parse header properly according to RFC 2616
* use 'tab' as whitespace as well as 'space'
* process header lines divided to several lines with whitespace
HttpHeader::GetMimeType: fix: trim whitespace chars according to RFC2616
HttpHeader::GetCharset: fix: properly find charset according to RFC 2616
* detect more than one whitespace
* use 'tab' as whitespace
* allow charset to be quoted
Merge pull request #3650 from Karlson2k/fix_pcre_utf8

Fix PCRE UTF-8 error (mostly for scrapers)
Merge pull request #3695 from Karlson2k/http_header_rfc2616

Fix: process HTTP header according to RFC 2616
[LINUX] Fix display of labelless mount points.

UDisks storage provider shouldn't assume volumes are in the GB range.
Merge pull request #3793 from FernetMenta/shader

LinuxRendererGL: make sure we have a shader defined
IPlayer: let player know on close if it will be reopened
paplayer: instruct AE to keep configuration when skipping tracks
AE: add interface method KeepConfiguration
ActiveAE: fix port comparison  in state machine
Merge pull request #3725 from fetzerch/bugfix-recordings

[pvr] Fix missing recordings
Merge pull request #3774 from FernetMenta/skiptrack

Inform (pa)player about intent to reopen on skipping tracks