cmake: Add FindIce.cmake

Switch from extremely limited Ice autoconfiguration to a full cmake
find_package implementation.  This

- autodetects Ice on all major platforms
- allows building with all supported Visual Studio versions on Windows
- autodetects the slice path on most platforms
- does version checking to ensure the Ice version is correct
- separately detects the Ice programs, headers, slice files and
  libraries so that any configuration or installation errors can
  be accurately reported, making diagnosis of Ice problems much
  simpler

On most platforms, it will now be possible to build without
explicit configuration of any Ice settings such as ICE_HOME and
SLICEPATH.  Where configuration is required, it will be
sufficient to set ICE_HOME or ICE_SLICE_DIR for most common
cases, while also allowing finer-grained configuration if
required.

If doing an out-of-tree cmake build, the autoconfigured Ice
settings are also used when running the java build for source
generation.  In-tree builds however will still require Ice
configuring up-front to allow the main build to work, though
build-cpp can still take some advantage of FindIce.
Expose private members in Sphinx API documentation
Replace all instances of L{ using Sphinx domain markup
Fix U{ and C{ references using Sphinx markup
Fix various warnings due to the exposition of private members
merge develop -D org: PR 2435 (cpp: RTypesI: use static locals in place of duplicated globals)
merge develop -D org: PR 2835 (Update OmeroPy/src/path.py)
merge develop -D org: PR 2875 (Matlab CZI job (rebased onto develop))
merge develop -D org: PR 2884 (fix #10766: add API method for changing original files' hasher)
merge develop -D org: PR 2895 (Reload groups after users added/removed)
merge develop -D org: PR 2902 (OmeroPy: src flake8 (I))
merge develop -D org: PR 2903 (Reset rndsettings)
merge develop -D org: PR 2905 (Renderings settings )
merge develop -D org: PR 2912 (Java8)
merge develop -D org: PR 2916 (Add 2008ServerR2 support to DropBox (rebased onto develop))
merge develop -D org: PR 2918 (Fix createMask.m)
merge develop -D org: PR 2919 (fix #7240: provide disk usage count)
merge develop -D org: PR 2920 (cmake: Add FindIce.cmake)
merge develop -D org: PR 2921 (Sphinx API: OmeroPy links review)
merge develop -D org

Repository: openmicroscopy/openmicroscopy
Excluded PRs:
  # PR 2585 aleksandra-tarkowska 'making time_zone and first_day_of_week configurable' (exclude comment)
  # PR 2363 dominikl 'Java Gateway API' (label: exclude breaking)
  # PR 2412 qidane 'Extra annotations' (exclude comment)
  # PR 2907 will-moore 'Preview panel like insight' (status: )
  # PR 2182 joshmoore 'Read only flag' (label: exclude)
  # PR 2403 aleksandra-tarkowska 'Send email' (label: breaking)
Already up-to-date.

Merged PRs:
  # PR 2435 rleigh-dundee 'cpp: RTypesI: use static locals in place of duplicated globals'
  # PR 2835 simleo 'Update OmeroPy/src/path.py'
  # PR 2875 sbesson 'Matlab CZI job (rebased onto develop)'
  # PR 2884 mtbc 'fix #10766: add API method for changing original files' hasher'
  # PR 2895 dominikl 'Reload groups after users added/removed'
  # PR 2902 sbesson 'OmeroPy: src flake8 (I)'
  # PR 2903 jburel 'Reset rndsettings'
  # PR 2905 dominikl 'Renderings settings '
  # PR 2912 jburel 'Java8'
  # PR 2916 ximenesuk 'Add 2008ServerR2 support to DropBox (rebased onto develop)'
  # PR 2918 sbesson 'Fix createMask.m'
  # PR 2919 mtbc 'fix #7240: provide disk usage count'
  # PR 2920 rleigh-dundee 'cmake: Add FindIce.cmake'
  # PR 2921 sbesson 'Sphinx API: OmeroPy links review'
Conflicting PRs (not included):
  # PR 2909 mtbc 'fix #11625: sanitize invalidly named FS paths'

Repository: openmicroscopy/bioformats
Excluded PRs:
  # PR 1015 qidane 'Messy binary' (exclude comment)
  # PR 1177 rleigh-dundee 'specification: Add metadata for HDF5 embedding' (exclude comment)
  # PR 858 melissalinkert 'Initial support for Veeco AFM data' (label: exclude)
  # PR 857 melissalinkert 'Initial support for Zeiss .lms files' (label: exclude)
  # PR 1249 PremyslFiala 'ND2 - Bug fixes' (user: PremyslFiala)
  # PR 816 melissalinkert 'Add support for multi-channel Volocity Clipping datasets' (label: exclude)
  # PR 1054 qidane 'Additional annotation points throughout the model' (exclude comment)
  # PR 1161 sommerc 'Initial CellH5 Reader class' (user: sommerc)
  # PR 1141 LeeKamentsky 'Reader for Amaris FlowSight .cif format' (label: exclude)
Updating 0bd1802..281e40f
Merged PRs (fast-forward):
  # PR 1257 sbesson 'Fix link to Volocity page (rebased onto develop)'
  # PR 983 melissalinkert 'Woolz: make sure the service is initialized when calling openBytes (rebased onto develop)'
  # PR 1242 bpindelski 'Fix wrong number of channels for images in fake SPW (fix #12501)'
  # PR 1204 rleigh-dundee 'cpp: Add PixelBuffer<> and VariantPixelBuffer'
  # PR 1253 melissalinkert 'Update version history for 5.0.3 (rebased onto develop)'
  # PR 1250 joshmoore 'Improve LOGGER levels in Memoizer (rebased onto develop)'

Merged PRs:
  # PR 978 berl 'Add writing of .v3draw format for easy loading with Vaa3D.'
  # PR 1136 melissalinkert 'Add initial support for reading BinaryOnly OME-TIFF datasets (rebased onto develop)'
  # PR 1154 melissalinkert 'Leica: prevent exception when linking EmissionFilter'
  # PR 1245 imunro 'Add reader for PicoQuant .bin files.'
  # PR 1252 imunro 'Add Example code or writing Plate data to ome-tiff.'
  # PR 1254 melissalinkert 'ND2: one more set of dimension parsing fixes (rebased onto develop)'
  # PR 1255 sbesson 'Fix ImageAcquisitionDate parsing for DeltavisionReader'

Repository: ome/scripts
Already up-to-date.

Repository: openmicroscopy/ome-documentation
Already up-to-date.

Merged PRs:
  # PR 929 ximenesuk ' DropBox configuration clarification (rebased onto develop)'
  # PR 930 sbesson 'Fix memory command on server upgrade page (rebased onto develop)'
  # PR 932 sbesson 'Update auto-generated properties'
  # PR 933 hflynn 'Include LDAP OR docs from Jake Carroll (rebased onto develop)'

Generated by OME-5.1-merge-push#381 (http://ci.openmicroscopy.org/job/OME-5.1-merge-push/381/)