[FIX] catch error in seekg

- catch error when seekg cannot go to the requested position and
  re-throw a sensible error message
[FIX] use std::streampos in CachedMzML (multiple fixes)

- use std::streampos to store positions in filestreams
- check for error condition before resize on untrusted input in
  readSpectrumFast / readChromatogramFast
- fix handling of positions received from tellg, instead use combination
  of seekg and ifstream::cur
[TEST] adapt test for CachedMzML
[FIX] use std::streampos in IndexedMzML

- use std::streampos which allows to address also larger files
[FIX] correctly read file position from XML into std::streampos
[TEST] add test
[FIX] properly release xercesc resources after use
[FIX] fix build for MSDataCachedConsumer_test after API change
Merge pull request #688 from hroest/fix/FileSizeLimit

Fix/file size limit